Upload
others
View
24
Download
0
Embed Size (px)
Citation preview
REPORT ON
Brainstorming Session for
Development, Management and Monitoring of
Oil and Gas Fields
22nd
July to 24th
July, 2009
Dev G Note: 1052
2
Oil India Limited Development Geological Note No. 1052
A Report on the Brainstorming Session on Development, Management and
Monitoring of Oil and Gas Fields held at Shillong during July 2009
I. INTRODUCTION
1.1 History of the oil and gas industry is replete with examples where it was believed that
hydrocarbon resources were dwindling and later it was proved that actually people had been
running out of ideas to locate them. This also includes some major discoveries of oil and gas.
Oil India has also not lagged behind in the share of major breakthroughs. Dedicated efforts by
generations of Oil Indians have helped OIL to complete fifty years of a remarkable journey in
the search of hydrocarbons. During this period, the company has established itself as the second
largest Oil and Gas Company in India in terms of total proved plus probable oil and gas
reserves and production. However the current industry scenario with its competitive
environment and challenges demands even more from the dedicated band of Oil Indians to
retain its position and strive ahead. It was in this backdrop that Chairman and Managing
Director Sri N.M.Borah mooted the idea of a brainstorming session for the younger generation
of geoscientists who have a bigger stake in this company in terms of years of service, to come
out with ideas that would aid OIL on its continuous path of growth, arresting any slippage down
the list of Industry Majors and to retain OIL`s position as a front ranking upstream company in
years to come. Chairman and Managing Director also suggested that the session should be
organized away from the workplace to ensure that the thinking process was not disturbed by
day to day routine activities of office as well as home.
1.2 The first brainstorming session on the exploration domain was organized from 15th to
18th March, 2009 at Kaziranga, Assam, where a total of 18 participants of varying ages, mostly
below 40 years, comprising of members from Geology, Geophysics and R&D disciplines, were
brought together on a common platform to brainstorm on emerging trends and ideas for future
exploration and development activities. The discussion that followed for the next three days
was guided by BP coaches to keep the session aligned with the objective as well as to provide
equal opportunity to all the participants. Over twenty five ideas were deliberated upon and the
outcome of the discussion, which had been systematically captured during the process, was later
presented to the E&D Top Team and the Executive Council in the presence of CMD and the
Board of Directors at Duliajan where the priority ideas as well as the road map to achievement
were described. Following the success of the first session, the second brainstorming session on
the Development, Management and Monitoring of Oil and Gas Fields was held in Shillong
from 22nd
July to 24th
July, 2009. The domain on which the deliberations took place was on the
Development, Management and Monitoring of Oil and Gas Fields and was conducted in a
format similar to the first session under the active guidance of the BP coaches. There were 18
participants in the second session and were drawn from disciplines like Geology, Reservoir,
Geophysics, Chemical, Production Oil and Gas, R&D, Well Logging, Drilling and Technical
Services. The list of participants is enclosed in Annexure I.
1.3 The inaugural and concluding sessions of the brainstorming sitting was graced by the
presence of Shri B.N.Talukdar, Director (E&D) accompanied by Sri. K.K.Nath, General
Manager (GS). With his thought provoking words and a detailed picture of the current Indian
Dev G Note: 1052
3
upstream hydrocarbon scenario, Director (E&D) set the tone for the intense sessions that
followed. Director (E&D) also highlighted the future energy demand in India, challenges ahead
of E&P companies with special reference to Oil India Limited and asked the participants to
contribute in OIL’s way forward by actively participating in the session and coming up with
new ideas.
.
1.4 The brainstorming session concluded on 24th
evening and culminated in a presentation
on the ideas generated during the three days of brainstorming session to Director (E&D). The
concluding session was also attended by Sri. A.K.Mahanta, General Manager (CC & PR) and
Sri. B.K.Borah, General Manager (Pipeline Services).
1.5 This document is a compilation of all the ideas and views of the group of participating
executives emerging out of the discussions that took place in the three-day brainstorming
session. The draft is structured to include the methodology used, ideas generated, comments
and conclusions thereafter drawn. Furthermore, the ideas generated in Shillong may also go
through further modifications over time. It may be mentioned here that action at various levels
may already have been initiated at different levels of the Company. However the discussions of
these ideas reinforce the belief and confidence that the participants have on that particular idea.
II. METHODOLOGY
2.1 The venue of the brainstorming session was Hotel Polo Towers in Shillong, Meghalaya.
Following the inaugural presentation by Director(E&D) where he discussed the current status of
the company in the context of the larger scenario of the upstream sector of the country, the
brainstorming session was conducted by Sri. P.K.Devchoudhry, Chief Coordinator BP, and his
team consisting of Sri. Bipul Das and Smt. Deepshika Deka. The methodology followed by BP
coaches for generation of creative ideas was named 3D Creative Process which could be
described as follows.
3 D Creative Process: The 3Ds in the process of creative thinking are Discovery, Dream and
Design.
2.2 During the discovery phase, the participants were asked to discover the strengths and
qualities of OIL as well as themselves individually. Each participant noted down his/her
strengths and qualities and that of OIL and shared the same with other participants. Based on
this exercise, a list of strengths and qualities for the company were prepared which were agreed
by all participants.
2.3 During the Dream phase, participants were asked to dream about the desired future,
given the strengths and qualities the company has. That is when they realized that it is possible
to achieve the desire goal.
2.4 In this state of mind, participants were taken to the Design phase by the BP coaches to
facilitate the group to generate creative ideas in the field of Development. The ideas in the field
of Exploration were subdivided in to two categories, Subsurface Assessment and Subsurface
Problems.
2.5 The participants were divided in to the domains of Sub-surface Assessment and Sub-
surface Problems. Each group came up with ideas and gave a presentation to the larger group.
During presentation and the discussion that followed, more ideas were generated and the
existing ideas were challenged and discussed within the group and refined wherever necessary.
Dev G Note: 1052
4
2.6 Thereafter, BP coaches advised each group to develop the action plan for implementing
each idea keeping in mind the following guiding questions
What results are expected?
What actions are to be taken for implementation of the ideas?
What are the milestones?
Who is to initiate?
2.7 Once the groups had prepared the action plan for implementation, they gave
presentations to the larger group, and finally on the concluding day, a presentation was given to
Director (E&D) and senior officials of the Company on the outcomes of brainstorming session.
III. IDEAS ON SUBSURFACE ASSESSMENT DOMAIN
3.1 The ideas formulated during the brainstorming session on the sub-surface assessment
domain were as follows:
1. Firm Field Development Plan
2. Detail Testing of Exploratory Wells as per International Practice
3. Upgrading In-house Formation Evaluation Capabilities
4. Delineation of Structures
5. 4D Seismic for Reservoir Monitoring
6. Full Wave Form Seismic Analysis
7. In-House Technology for High Angle (J-Bend), horizontal & Slim-hole Drilling
8. Mud Policy as per Field Requirement
9. Inclusion of Modern Drilling Rigs
10. Solid Control Equipment
11. Mud Logging unit
12. Drill in Paper
Idea No. 1 : Firm Field Development Plan
The participants were of the opinion that a systematic development plan should be followed
only after proper appraisal/delineation has been conducted for newly discovered structures.
Systematic data acquisition should also be part of the plan. Furthermore, empowered asset
teams which would include Geophysicists, Development Geologists, Operation Geologists,
Reservoir Engineers, Production Engineers, Geochemists should manage field development
plans in specific group of fields within OIL’s operational area. This would promote a shared
understanding of the fields and a shared roadmap for the field. Systematic data collection
should be conducted on a routine basis in all the fields with constant monitoring of pressure
production behavior.
Expected Results:
Maximization of recovery
Accretion of reserve
Better understanding of future drilling plan
Actions:
Formation of Asset Management Team (AMT) including Geo-science,
Drilling, Chemical, Production, Field Engineering etc.
Dev G Note: 1052
5
Formulation of a full scale development plan by AMT at the very beginning
stage including Geo-mechanical study, Conventional coring, PVT analysis,
periodic BHP measurements, Pressure Transient Analysis (PTA) on routine
basis for development of sub-surface model. Recording of CMR/NMR logs
for refining sub-surface model.
Hook-up surface network with sub-surface model to form integrated Asset
Model
Develop reservoir management plan viz. artificial lift, water injection
/IOR/EOR
Implementation of continuous down-hole monitoring systems after assets are
being put on production
When to Start: To initiate with immediate effect
Who has to Initiate: RCE
Milestones:
Formation of Asset Management Team
Strategic plan to develop the field
Implementation of the development plan for the Asset
Idea No. 2 : Detailed Testing of Exploratory Wells as per International Practice
The participants opined that detailed testing of all prospective sands of each exploratory well as
per international practice should be initiated with immediate effect. This will lead to better
understanding of the reservoir for future development and also in the planned accretion of
reserve. A feasibility study may need to be carried out to see the benefit of using workover rigs
for carrying out the detailed testing vis-à-vis drilling rigs.
Expected Results:
Good understanding of the reservoir for future development
Accretion of reserve
Actions:
Testing of all prospective sands.
Feasibility of using dedicated work-over rigs vis-à-vis drilling rigs for testing
purpose.
Drilling of S-bend well from same plinth to compensate production loss as
an interim strategy.
Extended well testing of the prospective zones: Extended well tests (EWTs)
are used to evaluate productivity and characteristics of a reservoir and can
complement seismic fault information.
When to Start: To initiate with immediate effect
Who has to Initiate: Head Operations (G&R)
Idea No. 3 :Upgrading in-House Formation Evaluation Capabilities
The wire line logs traditionally have been the undisputed, best means available of quantifying
and analyzing the in-situ formation. Wireline logging devices have been developed and refined,
capable of precisely measuring an extremely wide range of petrophysical and geological
Dev G Note: 1052
6
properties. Over the years advances have been made in a variety of logging technologies,
enhancements have taken place in log data acquisition which include higher data sampling and
transmission rates and expanded computer capabilities to process log data and to control
logging operations. New accurate, cost-effective methods for addressing a variety of formation
evaluation challenges have been developed.
The in house capabilities of well logging have been limited to the basic wire line logging and
well completion jobs. The up gradation of in house logging capabilities including technology
procurement and competency build up will not only serve the company better, but also develop
the capability of well logging department to act as service providers to other companies as a
business development venture. The competency build up will also help in better supervision and
quality control of the logs recorded and interpreted by the service providers.
Creation of a multidisciplinary Formation Evaluation group will help in the assimilation of the
data acquisition and data interpretation groups which in turn will facilitate better reservoir
management.
Expected Results:
Improved formation evaluation
Reservoir delineation/ modelling
Reduced dependency on service providers for well logging jobs
In-house knowledge enhancement
Service providers for the other E&P companies
Actions:
Procurement of advanced specialized tools
Competency build-up to take up specialized logging jobs
When to Start: To initiate with immediate effect
Who has to Initiate: GM (GS)
Milestone:
Procurement of advanced specialized tools
Manpower Resource Readiness
Actual Data Acquisition
Idea No. 4 : Delineation of Structures
Another view of the participants was that the delineation of discoveries should be conducted by
aggressive drilling of extension/ out-step wells and suggested tentative share of drilling efforts
on Exploration should be 30%, on Delineation being 30% and on Development including
IOR/EOR wells being 40%. Also redefining the structures based on well evidence must be
initiated with immediate effect for conversion of 2P/3P reserve to 1P.
Expected Results:
Conversion of reserves : 3P 2P 1P
Actions:
Refine structure based on well evidence
Sharing of drilling efforts on Exploration wells: 30%, Delineation wells:
30%, Development wells : 30% and water injection or IOR/EOR wells: 10%
Dev G Note: 1052
7
Refine structure based on well evidence
When to Start: To initiate with immediate effect
Who has to Initiate: RCE
Idea No. 5 : 4D Seismic for Reservoir Monitoring
In contrast to 3D seismic, which is an exploration and development tool, 4D seismic is quickly
becoming a vital reservoir management tool. Time-lapse seismic images may identify bypassed
oil to be targeted for infill drilling, and add major reserves to production to extend a field’s
economic life. 4D seismic may be used to monitor the progress of injected fluid fronts (water,
gas etc.) that can help in optimizing injection programs. 4D seismic can map reservoir
compartmentalization and the fluid-flow properties of faults (sealing versus leaking).
Expected Results:
Monitoring fluid front movement
Identification of remnant hydrocarbons
IOR/ EOR planning
Revitalization of producing and declining fields
Actions:
Developing capabilities for in-house processing and analysis of the
time-lapse data.
When to Start: To initiate with immediate effect
Who has to Initiate: GM (GS) (for Acquiring, Processing and Interpreting Data)
GM(G& R) (for Planning & Development)
Milestones:
Acquisition of base and reference surveys
Processing of time lapse data
Identification of fluid movement and remnant hydrocarbon
Proposal for drilling
Idea No. 6 :Full Wave Form Seismic Analysis
Conventional seismic inversion techniques involve transforming the Post-Stack seismic data
into P-impedance, from which we were able to make some predictions about lithology and
porosity. However, predictions based on this technique are limited, since P-impedance is
sensitive to lithology, fluid and porosity effects, and it is difficult to separate the influence of
each effect. To perform stable and more accurate interpretation of inversion results, full elastic
inversion is required to be performed.
Full wave inversion technique, unlike conventional inversion, not only uses multi-component
information (.i.e. P-wave & S-wave) but also the pre-stack gathers to estimate more accurately
the P-impedance, S -impedance and density which no other inversion technique can yield. Full
wave inversion can yield information about lithology, fluid and porosity.
As OIL has developed in-house capability of acquiring full waveform data (.i.e.
multicomponent) it is essential to develop in a phased manner in-house capability for
processing, interpretation and analysis of full waveform data through training and work-
Dev G Note: 1052
8
association with experts. The first phase should cater for development of knowledge base for
conventional post-stack seismic inversion. The second phase of the project will develop
capability for Simultaneous Angle Dependent Inversion and third phase will be to implement
full fledged working capability of full waveform inversion.
Expected Results:
Utilization of multi-attributes with confidence
Identification of reservoir fluid and lithology
By-passed oil identification
Actions:
Developing in-house knowledge base and capabilities for full-waveform seismic
data processing and multi-attribute analysis
In-house resource setup for full-waveform processing
When to Start: To initiate with immediate effect
Who has to Initiate: GM (GS)
Milestones: Acquisition of full waveform data
Processing of data using in-house capability, developed by training and work
association.
Prospect identification and technique validation
Idea No. 7 : In-House Technology for High Angle (J-Bend), Horizontal & Slim-hole
Drilling
Drilling Technology has made rapid progress since the drilling of first successful oil well in
1859 by cable tool drilling method. Advanced drilling methods like extended reach drilling,
multilaterals, casing while drilling, coil tubing drilling are increasingly becoming the norms
of the industry. In many E&P companies, drilling of conventional vertical wells have mostly
been replaced by horizontal, multilaterals, extended reach wells. Participants therefore felt
that we should also adapt to these advanced technologies by building up in-house
competency.
Expected Results:
Core competency
Productivity enhancement
New business opportunity by providing services
Actions:
Formation of team for identifying and procurement of technology
Identification of wells
When to Start: To initiate with immediate effect
Who has to Initiate: RCE, GM (OD&RS)
Milestones:
Identification and application of best available technology
Dev G Note: 1052
9
Develop in house capabilities
To initiate with immediate effect
Idea No. 8 : Mud Policy as per Field Requirement
The group felt that mud parameters should be designed based on geological, lithological and
geo-mechanical studies of the specific field. There should be detailed study of the
geomechanical properties and pressure regime existing in the particular field and use the same
as input for planning the bit, hydraulics and mud policy.
Expected Results: Minimum formation damage
Higher productivity
Minimize down-hole problems
Actions:
Geo-mechanical study
Pore pressure study
Designing of drilling fluids as per field specifications
When to Start: To initiate with immediate effect
Who has to Initiate: Head (Chemical)
Milestones:
Identification of field for implementation.
Collection of field data and categorization of field.
Selection of drilling fluids as per field requirement
Idea No. 9 : Inclusion of Modern Drilling Rigs
The participants felt the need of refurbishing /upgrading our drilling rigs with modern
equipments as well as procurement/hiring of modern drilling rigs for more efficient and
safer drilling performance. The rigs may be equipped with top drive system, variable
frequency drive, auto driller, better rig hydraulics etc. Some of these rigs may be custom
made for drilling high angle/ extended reach wells in cluster.
Expected Results: Achievement of drilling targets
Minimize down-hole problems and formation damage
Higher productivity
Actions:
Formation of multidisciplinary team for selection of the best available drilling
rigs
Procurement/ Hiring/ Refurbishment of drilling rigs
When to Start: To initiate with immediate effect
Dev G Note: 1052
10
Who has to Initiate: GM (ODRS)
Milestones:
Identification and selection of drilling rig
Procurement/ Hiring as well as refurbishing of existing rigs and training for
operations
Idea No. 10 : Solid Control Equipment
The goal of all modern solids control systems is to reduce overall well costs through the
efficient removal of drilled solids while reducing and minimizing the loss of drill fluids.
Additional goals include worker health and safety and environmental compliance. The greater
the percentage of drill solids removed and drilling fluid preserved, the higher the operating
efficiency.
In most of our drilling rigs, the solid control systems are not fully functional which greatly
hampers the drilling performance. Participants therefore felt that all our rigs should be fitted
with industry standard solid control systems.
Expected Results: Minimize down-hole problems and formation damage
Less wear and tear of equipments
Minimum down time
Actions:
Implementation of industry standard solid control system in all drilling rigs
When to Start: To initiate with immediate effect
Who has to Initiate: GM (ODRS)
Milestones:
Identification and selection of solid control system.
Procurement of solid control system and training for operations
Idea No. 11 : Mud Logging unit
Mud Logging Unit is an information hub at the wellsite which brings information on the
drilling process in real time to the decision makers. (onsite or at any remote location). Mud
Logging provides subsurface geological information while drilling a well which can help in
identification of pay zones and fluid contacts. The unit provides electronic monitoring of
drilling parameters such as weight on bit, torque, penetration rate, mud levels, pump speed
which can help to optimize drilling process, geosteering etc. Mud Logging also provides critical
safety functions such as determining pore pressure, kick control and ambient gas
monitoring. Furthermore, with the identification of low resistivity pay, thin reservoir zones and
reservoirs with secondary gas caps in OIL’s area of operation it is imperative that the reliance
on the human factor should be supplemented by monitoring facilities available in the MLUs.
While Mud Logging Units are being used during drilling of most exploratory wells, it should
also be used for monitoring during the drilling of development wells as well.
Dev G Note: 1052
11
Expected Results: Better well management during drilling
Reduction on down-hole problem and formation damage
Improvement in geo-modelling
Actions:
Installing Mud Logging Units (MLU) in all drilling locations
Connectivity of MLU with Drilling, Chemical & G&R Dept.
When to Start: To initiate with immediate effect
Who has to Initiate: GM (G&R)
Milestones:
Identification and selection of MLU
Hiring of MLU
Commissioning of MLU and making data available online to all concerned
departments
Idea No. 12 : Drill in Paper
It was strongly felt by the participants that as practiced in the Industry a document enlisting the
detailed step by step operational procedure of each well should be prepared prior to
commencement of drilling. This document would also incorporate the geologic prognosis, basic
well data, HSE details, drilling fluids programme, programmes for bit and hydraulics, wellhead
and BOP configurations, cementing as well as the administrative and data communication
channels.
Expected Results: Better Well management during drilling
Reduction in down-hole problem and formation damage
Drilling target achievement
Cost control
Actions:
Standardization of existing GTO/ Depth Data Drilling Policy
Benchmarking of drilling practices with respect to fields
Condition monitoring of all surface equipments
When to Start: To initiate with immediate effect
Who has to Initiate: GM (ODRS)
Milestones:
Formation of Multidisciplinary Team to gather well data
Arranging the resources
Final Documentation
Dev G Note: 1052
12
IV. SUBSURFACE PROBLEMS AND ISSUES DOMAIN
The following subsurface issues / problems were discussed during the brainstorming session:
1. Delineation of Thin Sands
2. Fault Transmissibility
3. Development of Thin Oil Column with Associated Gas Reservoirs
4. Exploitation of Bypassed Hydrocarbon
5. Declining Reservoir Pressure
6. Monitoring of Water Injection Reservoirs
7. Declining production from Aged Fields
8. Near Balanced or Under Balanced Drilling
9. Minimizing down hole complications while drilling
10. Cementing Failure (Primary & Secondary)
11. Wells With Presence of Corrosive Gas (CO2)
12. High GOR in Producing Wells
13. High Water Cut in Producing Wells
14. Sand Ingression in Producing Wells
15. Intelligent Field
16. Wax Deposition
17. Corrosion of tubing in water injection wells
Issue No. 1 : Delineation of Thin Sands
Delineation of thin sands in OIL is mostly based on well-to-well correlation of conventional
well logs and geological information obtained from drill cuttings and cores. There is a certain
degree of uncertainty associated with the continuity and interconnectivity of the sands.
The industry is making increased use of sequence stratigraphic analysis for deciphering the
complexities of determining sand continuity. Recent technological advances in novel, high-
resolution logging instrumentation, increased high-sampling rate data acquisition, advances in
high-resolution signal processing (e.g., deconvolution) techniques, and newly developed thin-
bed interpretation methods now allow an improved reservoir description of such sequences.
Improvements include reliable net pay count; enhanced well-to-well correlation; better thin-bed
correlation of well log, core, and test data.
The participants felt that there should be increased use of the techniques and technology in OIL
on priority basis for a more accurate identification and quantitative evaluation of thin oil and
gas-bearing sands.
Proposed Actions:
High order sequence stratigraphic analysis.
3D Seismic designing for deeper horizons.
Spectral decomposition studies.
Developing capability for wavelet based analysis techniques.
Hiring of Domain Experts.
Expected Results:
Reserve Accretion.
Formulating development plan of thin reservoirs.
Dev G Note: 1052
13
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM (GS) for carrying out the necessary seismic aquisition and analysis
GM (G&R) for formulating development plan of thin reservoirs
Milestones :
Completion of acquisition of broadband data
Spectral analysis and identification of stratigraphic traps
Identification of reservoirs and development plan of thin reservoirs
Issue No. 2 : Fault Transmissibility
Faults control not only the presence of hydrocarbon in a trap but also how much and how they
are distributed. Traditionally flow across faults have been estimated based on reservoir pressure
and production behaviour. In reservoir simulation, the cross-flow behavior of faults has
traditionally been treated simply as a calibration parameter for history matching or by applying
a transmissibility multiplier uniformly to all faults. There is now a growing consensus within
the industry that the correct characterization of fault seals is a crucial missing step in the
reservoir modeling-to-simulation workflow.
Study of fault transmissibility will help in better understanding of reservoir
compartmentalization which will lead to better reservoir management.
Proposed Actions:
Fault Seal analysis.
Pressure Transient analysis.
Tracer injection
Expected Results:
Robust Dynamic Modeling.
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(G&R)
Milestones :
Identification of Juxtaposition relationship.
Identification of Clay Smearing.
Identification of Reservoir Compartments.
Issue No. 3 : Development of Thin Oil Column with Associated Gas Reservoirs
In Nahorkatiya and Jorajan fields a number of reservoirs with thin oil column (STOIIP < 1 MM
Std Kls) and large gas cap are lying idle pending a suitable development strategy. The
conventional way to produce an oil reservoir that has a gas cap is to produce only from the oil
column while keeping the gas cap in place so that it can expand to provide pressure support.
However, it is difficult to extract oil from these reservoirs through conventional vertical wells
since gas breaks through very early. Gas cannot be produced from these reservoirs since
production of gas would lead to loss of reservoir energy and hence poor recovery of oil.
Dev G Note: 1052
14
Participants felt that a suitable development strategy needs to be formulated for these reservoirs
which could either be:
1. Gas-cap blowdown. Some oil is expected to be produced with high rate of gas
production.
2. Utilization of horizontal wells to accelerate oil recovery prior to gas cap blow down.
However, a detail modelling of the reservoir would be necessary for this for proper
placement of the horizontal wells.
Proposed Actions:
Review of thin oil column reservoirs
Formulation of development plan
Expected Results:
Enhancement in production
1P reserve accretion.
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(G&R)
Milestones :
OIL team to visit BG’s Mukta-Panna Field to gather first-hand information.
Short-listing of such reservoirs.
Reservoir study.
Strategy Development
Issue No. 4 : Exploitation of Bypassed Hydrocarbon
The participants felt that lot of bypassed hydrocarbon is still left in our matured fields.
Advanced techniques like cross well resistivity may be implemented to identify these bypassed
zones which can then be exploited through suitable infill drilling. Slim-hole sidetracks can be a
low-cost alternative to drilling new wells. Many wells in our oilfields have been temporarily
abandoned or are lying idle due to downhole complications which can be utilized for drilling
side-track wells.
Additionally in fields like Nahorkatiya, some oil may be left in the crestal part of reservoir (attic
oil) which can be exploited through horizontal wells or maximum reservoir contact (MRC)
wells. An MRC well by definition is a multilateral horizontal well with more than five km of
total contact with the reservoir rock.
Proposed Actions:
Identification of bypassed oil through new technologies like interwell resistivity
logs.
Utilization of idle wells through window cutting and drilling sidetrack/
multilateral wells.
Exploitation of attic oil through horizontal wells / MRC wells
Expected Results:
Enhancement in production.
Enhancement in 1P reserves.
When to Initiate: To initiate with immediate effect
Dev G Note: 1052
15
Who has to Initiate: GM(G&R)
Milestones :
Reservoir modelling to identify of bypassed oil.
Identification, prioritization and probing of candidate wells for window cutting.
Acquisition of tools and technology.
Drilling of sidetrack wells/horizontal/multilateral wells
Issue No. 5 : Declining Reservoir Pressure
A total of fourteen reservoirs of Nahorkatiya, Jorajan, Moran and Shalmari are presently under
water injection. Apart from these fields there are some other fields including Eocene fields
where reservoir pressure is declining rapidly. Water injection needs to be extended to all these
fields urgently. Participants felt that the conventional way of converting old wells to injectors
may not be sufficient and new injection wells are needed which can be drilled at optimal
locations to provide better sweep efficiency.
Another issue, which needs to be deliberated urgently is re-injection of produced water into the
reservoir. Not only will this be more compatible to the reservoir, but more importantly it will
save some of the precious fresh water resource which is presently being used for injection
purpose.
A study on IOR/EOR application in major Eocene fields is presently being carried out by M/s
Halliburton. Additionally, a pilot project on water injection in Eocene reservoir of Kamkhat
field is being taken up, which will give better understanding of water injection process in
Eocene reservoirs.
Proposed Actions: Aggressive water injection scheme to arrest reservoir pressure decline.
New water injection wells need to be drilled as few old wells are available for
conversion.
Optimal location of injectors.
Produced water re-injection.
Expected Results:
Better Reservoir Management
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM (G&R)
Milestones :
Short-listing of reservoirs.
Identification of injection patterns.
Drilling/conversion of injection wells.
Issue No. 6 : Monitoring of Water Injection Reservoirs
Surveillance of water injection projects is very critical and need to be carried out more
efficiently. At present only basic surveillance techniques are applied which includes monitoring
Dev G Note: 1052
16
of injections rates and pressure production behaviour of the reservoirs. However, all
measurements are to be taken accurately for any meaningful study. Individual well injection
pressure and rates need to be measured and not allocated. In any waterflood project, every
injection well should be equipped with its own water flow meter. It is impossible to evaluate
waterflood performance without individual well injection rate and cumulative injection data.
More advanced surveillance techniques may also be implemented like, use of streamline
simulators, time lapse 3D seismic, PLT combined with high precision thermal logging etc.
Proposed Actions:
Streamline simulators.
Monitoring based on 4D seismic.
PLT.
Downhole memory camera
Expected Results:
Enhancement in Recovery.
Better Reservoir Management.
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM (G&R) for building reservoir model and formulation of action plan
GM(P-Oil) for implementation and day to day monitoring
Milestones :
Building of reservoir models.
Initiation of 4D seismic.
Implementation of Action Plan formulated for the reservoir
Issue No. 7 : Declining Production from Aged Fields
Declining production from our mature fields like Nahorkatiya, Moran, Jorajan, was a concern
for the participants. Although these fields are on production for the last four to five decades, the
participants felt that there is more oil left in these fields which can be extracted through suitable
IOR/EOR applications.
The primary phase of oil production from a reservoir depends on its existing natural energy
source. This primary process is normally supplemented early in the life of the reservoir by
secondary recovery or improved oil recovery (IOR) processes consisting of gas injection and
water flooding. Tertiary or EOR methods are applied at the end of the secondary phase. They
can be thermal, miscible or chemical processes which attempt to sweep out as much as possible
of the remaining oil.
Although OIL has successfully implemented secondary recovery processes like gas and water
injection in some of its reservoirs and polymer flooding in one reservoir, no other field scale
EOR projects have been implemented.
Due to a perception of high investment risks associated with EOR, the associated decision-
making workflows demand screening procedures, simulation exercises and detailed economic
evaluations. Such a study is presently being conducted by M/s Halliburton on application of
IOR/EOR in the Eocene reservoirs of Dikom, Kathaloni, Tengakhat and Chabua. Similar
Dev G Note: 1052
17
studies should also be carried for other matured fields. This may be followed by laboratory
studies and pilot projects of identified EOR methods.
Proposed Actions:
Multidisciplinary team to identify suitable EOR schemes for matured fields.
Pilot project of identified EOR methods
Expected Results:
Enhancement in Recovery.
Enhancement in 1P Reserve accretion.
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM (R&D)
Milestones :
Identification of suitable EOR schemes based on the present condition of the
ageing fields
Build up of infrastructure.
Implementation of pilots
Issue No. 8 : Near Balanced or Under Balanced Drilling
These techniques of drilling greatly reduce the damage caused to the formations because of
over balanced drilling. Induction of the system will minimize damage to the formations,
greatly reduce downhole problem in drilling and facilitate easy activation of the reservoirs.
A study has been conducted recently by M/s Weatherford to carryout screening of short
listed reservoirs and conduct feasibility studies of candidate reservoirs for successful
application of UBD technology. The consultant has recommended application of UBD
technology for drilling horizontal wells in the Makum Barail 4th
+5th
sand reservoir. Once
this technology is introduced successfully, it can be applied to more challenging areas like
highly depleted reservoirs of Nahorkatiya and Jorajan fields.
Proposed Actions:
Study of the reservoir characteristics
Identify the wells to be drilled
Feasibility study
Building up in house expertise / hiring services.
Installing necessary infrastructure.
Expected Results:
Minimum Formation Damage.
Reduction in down-hole problems.
Easy activation.
When to Initiate: To initiate with immediate effect
Who has to Initiate: Head(Ops)-G&R
Dev G Note: 1052
18
Milestones :
Pilot Project in Baghjan field for Near Balanced drilling
Pilot Project in depleted reservoirs of Jorajan, Nahorkatiya fields.
Issue No. 9 : Minimizing down hole complications while drilling
Several complications can occur during drilling operation like hole collapse, stuck pipe, blow
out situations etc., leading to loss of rig time, increased cost and even hole abandonment. Some
of these complications can be handled through proper planning, monitoring and use of
advanced technologies.
Participants unanimously felt that all drilling rigs should be upgraded to industry standards.
Periodic failure analysis of vital rotary parts should be carried out which can be done through
hand held thermal imaging equipments and also by using Condition Based Monitoring gadgets.
Geomechanical studies can be carried out to predict the most optimum drilling parameters to be
used for stable, safe and efficient drilling. Casing While Drilling can be used to drill through the
problematic zones. Using drillable bits with retrievable BHA the hole can be further deepened
or the bit may be left behind once TD is reached. Extended / Ultra Extended / Multilateral
technologies will greatly help us in reaching out to inaccessible reservoirs and can also
eliminate the problem of land acquisition. Shallower wells can be drilled faster with coil tubing
drilling. Additionally, real time monitoring of drilling operations can address some of the
drilling risks directly—and immediately.
Proposed Actions:
Geo mechanical studies.
Periodic failure prediction analysis of vital rotary drilling equipment like
Thermal Imaging, Wear particle analysis etc.
Incorporation of software for designing casing and drill string.
Mandatory use of industry standard solid control equipment.
Field specific drilling mud policy.
Real time monitoring system for all rigs
Incorporation of Drillings Rigs with Top Drive system.
Induction of new drilling technologies like CWD in geologically challenging
formations.
Induction of extended/ultra extended/multilateral drilling technologies to
enhance reservoir accessibility with fewer wells.
Induction of CTD for wells up to 3000 m.
Build-up in-house expertise / hire services
Expected Results:
Increase in Commercial Speed.
Less exposure of the open hole sections.
Lower cost per meter drilled.
Reduction of Caving, Mud Loss, Stuck Pipe and Fishing
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(G&R), GM(GS), GM (OD&RS)
Milestones :
Use of drill string design in the first well.
Dev G Note: 1052
19
Results of Geomechanical studies.
Mud parameters within desired limits.
Feasibility study by ODRS & Electrical Engg Dept.
Issue No. 10 : Cementing Failure (Primary & Secondary)
Cementing is a critically important operation in the construction of any well by providing a
continuous impermeable hydraulic seal in the annulus, preventing any uncontrolled flow of
reservoir fluids behind the casing. Many serious problems can arise from uncontrolled flows. It
was felt by the participants that problems of isolation failure, losses in well productivity, flow
behind the casing along the annulus could be drastically reduced by further improving our
cementing techniques and technology
Proposed Actions:
Making the existing mixing unit operational.
Procurement of new cementing units with latest technology.
Hiring of service providers for cementing jobs in complicated wells.
Low density cement for gas wells
Self healing cement
Expected Results:
Reduced water cut
Enhancement of production
Less work over jobs
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(OD&RS)
Milestones :
Rectification of fault in the existing non functional unit.
Locating suitable suppliers for quality cementing unit.
Procurement of such equipments.
Utilizing the service of the service providers.
Issue No. 11 : Wells With Presence of Corrosive Gas (CO2)
In the recently discovered Mechaki field, a relatively high CO2 content (around 5%) has been
observed in the gas stream. Presence of CO2 in high pressure/high temperature wells as in well
Mechaki-2 along with water production can be detrimental to the wellbore and well tubulars
and fittings. It was therefore suggested that a proper study should be carried out to identify
suitable corrosion inhibitors as material specifications for sub-surface assembly. Since a
number of locations have been released for drilling in this field, all future wells should be
equipped to tolerate the presence of CO2.
Another problem envisaged was that since Portland cements are typically used to cement
casings, cement behind casing is susceptible to acid attack by dissolved carbon dioxide which
forms carbonic acid. Particularly at elevated temperatures, continual influx of carbonic acid
convert Portland cement to a soft amorphous gel through a variety of reactions. It was therefore
suggested that use of CO2 resistant cement may be tried in such wells.
Dev G Note: 1052
20
Proposed Actions:
Identification and application of suitable CI
Drawing of specification of sub surface assembly
CO2 resistant cement
Expected Results:
Maintain integrity of well tubular and fittings
Extending the producing life of the well by eliminating failures due to corrosion
When to Initiate: To initiate with immediate effect
Who has to Initiate: GGM (Production)
Milestones :
Corrosion studies for screening of suitable CI in R & D Lab.
Procurement and injection of suitable CI based on lab results.
Drawing of specification of sub surface equipments based on fluid characteristic
by Production Department with the help of corrosion experts.
Procurement and completion of future wells with specified sub surface
equipment
Issue No. 12 : High GOR in Producing Wells
The conventional way to produce an oil reservoir with a gas cap is to produce only from the oil
column while keeping the gas cap in place so that it can expand to provide pressure support.
Depending on geometry, reservoir dip angle and oil production rates, gas can either cone down
to the oil producers or fingering intothe oil column, leading to substantial increases in gas-oil
ratios of the oil producers. In general high producing GORs lead to lower recoveries and all
practical steps should be taken to keep the producing GOR as low as possible.
In fields like Tengakhat, a number of wells are producing with high GOR indicating that part of
gas cap is being resulting in loss of reservoir energy. This would lead to lower ultimate
recovery if no corrective measures are taken. Participants therefore felt the need to identify such
high GOR wells and take necessary corrective actions.
Proposed Actions:
Controlled production
Expected Results:
Conservation of reservoir energy
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(P Oil)
Milestones :
Identification of high GOR wells.
Controlled production.
Dev G Note: 1052
21
Issue No. 13 : High Water Cut in Producing Wells
As fields mature, water cuts in most oil and gas wells increase and the source is either
formation water or injected water used for reservoir pressure maintenance. Usually, the lower
the API gravity of the oil the greater the chance of water production because low-gravity oils
typically are much more viscous and hence have lower mobility. Also, heterogeneities
encountered in reservoir rocks can cause water channeling through higher permeability streaks,
hairline fractures, near-well bore water and/or gas coning, or a combination of these
phenomenon.
Proposed Actions:
Selection of suitable WOR control chemicals
Hiring of experts.
Expected Results:
Reduction in formation water production
Increase in oil production
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(Production Oil)
Milestones :
Identification of suitable chemicals.
Application of the chemicals in-house or through the help of consultants.
Issue No. 14 : Sand Ingression in Producing Wells
Sand entering production wells is one of the oldest problems faced by oil companies, and one of
the toughest to solve. Production rate may be reduced to ensure that drawdown is below the
point at which the formation grains become detached. More subtly, selective perforation may
avoid zones where sanding is most likely. However, both options reduce production, which may
adversely affect field economics. The other option is to physically restrain sand movement with
slotted liners, sand screens, gravel pack etc.
Gravel pack jobs done recently in some of the wells in Makum –Hapjan areas have given
encouraging results. More sand prone areas need to be studied for application of this
technology. In addition, future horizontal wells in Hapjan field may be completed with Inflow
Control Device (ICD) and sand screen which can help to mitigate sand problem/water coning
and enhance production.
Proposed Actions:
Immediate action can be initiated by the Production group with the help of G&R
group and service providers in the remaining fields.
Representative core studies to analyze critical draw down pressure required for
preventing sanding problems.
Completion of future horizontal wells in Hapjan with ICDs and sand screen.
Expected Results:
Reduction in surface as well as sub surface problems
Dev G Note: 1052
22
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(Production Oil)
Milestones :
Identification of candidates.
Implementation of gravel pack.
Issue No. 15 : Intelligent Field
New technologies are transforming how oilfields operate. Intelligent oilfield is one such
technology which can help oil companies get the most out of their existing fields and establish
successful new fields in remote and harsh areas. By continuously collecting real-time data from
each well and deploying the right skills, tools and work processes in a collaborative way,
companies can instantly create an intelligent enterprise to monitor and control assets and
optimize recovery on demand, from wherever the people or oilfields are.
The participants envisaged such a system for OIL where all data from seismic to production
would be transmitted using wireless technology to a centralized data center. Individual wells
would be equipped with downhole controls and sensors which would help in real time
transmission of pressure production and other reservoir data. The data center would have
facility for real time visualization of all data which would help in quick decision making
process and hence improve operational efficiency.
Proposed Actions:
Identification of suitable field for pilot project
Expected Results:
Real Time Surveillance
Reservoir Management and Production Optimization
Improved Operational Efficiency
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM (P Oil)
Issue No. 16 : Wax Deposition
Wax is a class of hydrocarbons that are natural constituents of any crude oil and most gas
condensates. There is a potential for the wax to crystallize and adhere onto surfaces like the
pipe wall in a tubular and thereby form a deposit layer which will increase with time and
eventually, in the worst case, completely block the line. Such deposition will reduce the
capacity of the line by decreasing the effective diameter and increasing the wall roughness and
thus the pressure drop in turbulent flow. Most often, the wax control strategy simply consists of
scraping the wax away from the pipe wall by regular scrapping. Recent developments have
taken place in the wax control strategy across the Industry. Suitable techniques and wax
inhibitors should be adopted as part of the strategy.
Proposed Actions:
Production department to identify additional wells where the technique can be
applied.
Dev G Note: 1052
23
Use of wax crystal modifier along with the Gas lift Gas
Coil tubing (CT) conveyed brush.
Expected Results:
Reduced scrapping activities leading to less chance of fishing.
Increase in production.
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(R&D)
Milestones :
Selection of suitable candidates.
Application of technology as per requirement.
Issue No. 17 : Corrosion of tubing in water injection wells
Integrity of water injection wells is a critical issue which can undermine the very purpose of
water injection. Most of the injection wells are very old and regular tubing / casing integrity
tests are not carried out. In some cases, severely corroded tubing have been recovered during
workover operations. This leads to the apprehension that the injected water may not be reaching
the target zones. It was therefore recommended by the participants that regular integrity tests
should be carried out in all water injection wells. Tubing of injection wells need to be replaced
with higher grade tubing e.g. L-80. Alternatively, use of GRE line tubing in injection wells may
also be looked into. Injected water should also be treated properly, especially with oxygen
scavengers prior to injection.
Proposed Actions:
Proper specification of the tubing.
Tubing integrity test periodically.
Prevention of corrosion due to oxygen by use of oxygen scavengers
Expected Results:
Improvement in water injection rate.
When to Initiate: To initiate with immediate effect
Who has to Initiate: GM(Prod-Oil)
Milestones :
Checking of tubing integrity at regular periodicity.
Replacement of defective tubing.
V. SOME GENERAL ISSUES / IDEAS
Apart from the above to domains, some general issues were also discussed. These were:
1. Study Center
2. Skill Enhancement
3. Well-Site Camps
4. Group Drilling & Gathering Station (GDGS)
5. Quality Control Cell
Dev G Note: 1052
24
1. Study Center
Proposed Actions: Setting up a study centre outside the operational area equipped with state of the
art hardware, software, and laboratory facilities.
Expected Results: Formation of full fledged study centre to can undertake basinal studies, regional
studies, studies of other basins of the world to provide detailed inputs in E&P
opportunities. The Centre would also address specific issues in line with the
system prevailing in other E&P companies like IRS, SHELL study centre.
When to Initiate: To initiate with immediate effect
Who has to Initiate: Management
Milestones :
Building of a relevant database
Focused study related to various subsurface issues
2. Skill Enhancement
Proposed Actions: Identification of domains in which it is required.
Recognize the training agencies.
Regular provision of Seminars/ Symposiums/ Workshops.
Corporate subscription to Onepetro.org.
Opening / conversion of existing facility to a full fledged study centre within
Duliajan (Library fully furnished and air-conditioned with access to internet
within Township / anywhere easily accessible)
Expected Results: Up gradation of knowledge and skills through better exposure
When to Initiate: To initiate with immediate effect
Who has to Initiate: Concerned Heads and Head-T&D
Milestones :
Creation of skilled and up-to-date workforce.
Better working culture in the organization
3. Well-Site Camps (for areas beyond 30 Km from Duliajan)
Proposed Actions: Concept of multidisciplinary team available near the drilling site (Camps) /
Centralized facilities to monitor nearby wells.
Expected Results:
Better Monitoring of well-site operations.
Dev G Note: 1052
25
When to Initiate: To initiate with immediate effect
Who has to Initiate: RCE
Milestones :
Quick decision and implementation
4. Group Drilling & Gathering Station (GDGS)
Proposed Actions: Appropriate land acquisition for to accommodate plinths of maximum number of
locations to be accessed both by S-Bend and J-Bend drilling.
Accommodating production setups and provisions for IOR/EOR facilities within
this Station.
Facilities for fluid offtake points
Residential facilities in the model of OIL’s Tanot (Rajasthan) complex.
Expected Results:
Centralized Land Acquisition for many wells
Better security and monitoring both for drilling, workover and production setups.
Quick decision and implementation
When to Initiate: Feasibility study may be initiated at the earliest.
Who has to Initiate: RCE
Milestones :
Identification of areas
Acquisition of land
Setting up of the GDGS
5. Quality Control Cell
Proposed Actions:
Material specification cell to be set up for drawing suitable specifications based on factors like
application, metallurgy, industry standards etc. to facilitate procurement of equipment,
consumables & spare parts vital in nature.
Expected Results:
Quality Assurance and reduction of premature failure of equipment, mechanical
components and consumables in Drilling and Production operations. This will
also lead to uniform code and standard across the company. In addition it will act
as deterrence against purchase of sub standard spare parts and equipment.
When to Initiate: To initiate with immediate effect
Who has to Initiate: Head-Materials, Head (Chemical), GM( R & D)
Milestones : Reduced subsurface equipment failures.
Dev G Note: 1052
26
Increase Cost effectiveness.
VI. CONCLUSION
5.1 Based on the ideas generated during the brainstorming session, a number of ideas have
been prioritized in the following Table. Furthermore, the number of actions on the ideas
generated during the session have also been prioritized as follows.
Priority Ideas
Setting up a study centre outside the operational area equipped with state of the art
hardware, software, and laboratory facilities.
Setting up of a Group Drilling & Gathering Station (GDGS)
Drill in Paper
QC Cell
Priority Actions
Requisite studies for formulation of Mud Policy as per Field Requirement
Building up of In-House Technology and expertise for High Angle (J-Bend),
Horizontal & Slim-hole Drilling
Actions related to subsurface problems and issues
VII. ACKNOWLEDGEMENT
6.1 The participants of the session are extremely grateful to Mr. N.M. Borah, Chairman and
Managing Director, for initiating the idea of the brainstorming session and providing a truly
learning experience for the participants. We would also like to place on record our sincere
gratitude to the OIL Management for providing us the opportunity to participate in this
wonderful session.
6.2 We are grateful to Sri B. N. Talukdar, Director (E&D) for his encouraging words and
setting the tenor at the beginning of the session. We shall remain grateful for his valuable
suggestions during our presentation on the outcome of the brainstorming session.
6.3 We are also thankful to Sri K.K. Nath, GM (GS) for his guidance.
6.4 The group is also overwhelmed by the meticulous planning and execution of the session
by the BP coaches, T&D department and Pipeline departments.
6.5 General Manager (G&R) has gone through the Note critically and his invaluable
suggestions/ comments are gratefully acknowledged.
Dev G Note: 1052
27
U. A. Dutta
PE (Oil)
P. K. Singh
Geophysicist
M. K. Banerjee
Geophysicist
N. Gogoi Senior Geologist
N. Deka
Senior Geologist
J. B. Borah
Senior Engineer (Prod Oil)
S. Intaz
Dy. SE (Prod Gas)
D. K. Borah
Suptdg. Chemist
Dr. J. Hazarika
Suptdg. Chemist
C. M. Pakhale
SE(Prod Gas)
D.M. Baruah
SE(Well Logging)
S. Deb
SE (Drilling)-TS
P. Dutta
SE (Reservoir)
K. Buragohain
Suptdg. Geologist
U.K. Doley
Dy. CE(Drilling)
J. Kumar
Dy. Chief Research Scientist
M. Ravishankar
Dy. Chief Research Scientist
I. Barua
Chief Geologist
Duliajan: November 2009
Copy: Director (Ops)
RCE
GM (GS) / GM (T&D) / GM (G&R) / Head TU / Chief Coordinator (BP)
File
Dev G Note: 1052
28
Annexure: I
Participants of the Brainstorming Session
Mr.U. A. Dutta, Production Engineer (Oil)
Mr.P. K. Singh, Geophysicist
Mr.M. K. Banerjee, Geophysicist
Mr.J. B. Borah, Senior Engineer (Prod Oil)
Mr.N. Deka, Senior Geologist
Mr.N. Gogoi, Senior Geologist
Mr.S. Intaz, Dy. Suptdg. Engineer (Prod Gas)
Mr. D. K. Borah, Suptdg. Chemist
Dr. J. Hazarika, Suptdg. Chemist
Mr.S. Deb, Suptdg. Engineer (Drilling)-TS
Mr.C. M. Pakhale, Suptdg. Engineer (Prod Gas)
Mr. D.M. Baruah, Suptdg. Engineer (Well Logging)
Mr.P. Dutta, Suptdg. Reservoir Engineer
Mr.K. Buragohain, Suptdg. Geologist
Mr.U.K. Doley, Dy. Chief Engineer (Drilling)
Mr.M. Ravishankar, Dy. Chief Research Scientist
Mr.J. Kumar, Dy. Chief Research Scientist
Mr. I. Barua, Chief Geologist