REGIONAL ASSOCIATION OF OIL, GAS & BIOFUELS SECTOR ...media.arpel2011.clk.com.uy/rane/6/5CNametala.pdf · Permanent Downhole Gauges in Campos Basin Permanent Downhole Gauges provide

10/10/2014

1

REGIONAL ASSOCIATION OFOIL, GAS & BIOFUELS SECTOR COMPANIES

IN LATIN AMERICA AND THE CARIBBEAN

Offshore Data Acquisition

System with Platform

Independent Monitoring

Reveals New Geological

View of Brazilian Giant FieldSpeaker: Cayo Nametala de Souza, Petrobras.

Authors: Cayo Nametala de Souza, Patricia Braga Gusmão, Ricardo

Huntemann Deucher, Yuri Sa Scaramussa, Petrobras.

86th ARPEL Experts Level Meeting (RANE) “Management of Reservoirs”

October 6-7, 2014 – Buenos Aires, Argentina

86th ARPEL Experts Level Meeting (RANE) “Management of Reservoirs“ – October 6-7 – Buenos Aires, Argentina

Contents

� Use of Permanent Downhole Gauges in Offshore Giant Oil Fields in

Campos Basin.

� SASMIc Technology

� Field Cases

o Fault Transmissibility

o Hydraulic connection between reservoirs

� Conclusions and Recommendations

2

10/10/2014

2


Permanent Downhole Gauges in Campos Basin

� Permanent Downhole Gauges provide a continuous, real-time source

of downhole pressure and temperature.

� Downhole data is widely used in reservoir management:

3

Production Well DHP

Water

Injection

Well Flow

Rate

4200 psi

scale

Evidence

of pressure

support.



� Permanent Downhole Gauges provide a continuous, real-time source

of downhole pressure and temperature.

� Downhole data is widely used in reservoir management:

4

Production

Well DHP

Water

Injection

Well DHP

Shutdown of other production

well of same reservoir

5700 psi

scale

Pressure gain on

reservoir due to

well shutdown

10/10/2014

3



� Although it’s sensors have incredible resolution, most of PDG usage is

during flow, when slight variations are undetectable.

� Shutting down wells for retrieving information is costly, and is not a

common practice.

� It is necessary to take advantage in any opportunity of data retrieval

from closed wells, in which the information is static, and slight

variations on the reservoir can be perceived.

� This information is even more valuable before the well’s first flow,

since there are no build-up effects on the analyzed data.

5

3 psi scale

Tide effects lower

than 1 psi detectable

on downhole pressure

Downhole Pressure in static condition


Contents


Campos Basin.


� Field Cases




6

10/10/2014

4


SASMIc Technology

� The SASMIc acronym stands for Signal Acquisition System with Independent Monitoring (in Portuguese) and consists of a compact device that can be managed by a Remotely Operated Underwater Vehicle (ROV) and inserted on the Subsea Christmas Tree for data retrieval.

� The well must be equipped with sensors (downhole or sea-bed) which provide the data, but does not have to be connected to the platform through umbilical. The SASMIc equipment provides power to energize the sensors and also stores the data in local hard disk, that can later be recovered and sent to the interested party.

7


Contents


Campos Basin.


� Field Cases




8

10/10/2014

5


Field Case 1 – Fault Transmissibility

� A fault crosses Reservoir A from north to south dividing it in two separate compartments.

� Although the fault has a large throw, which gave the initial idea to be a sealing fault, it was not possible to conclude in advance if both compartments were indeed hydraulically disconnected.

� The wells were drilled considering that both scenarios, Sealing Fault or Transmissible Fault, were possible.

9



� The drilling and production schedule of Reservoir A had Well A-P1 finishing its completion several months before beginning its production.

� Meanwhile, wells A-P2, A-P3 (Producers) and A-I1 (Water Injector) would begin operations on the other side of the fault, and it was suspected that some variation could be detected on downhole sensors of A-P1

� Knowing this beforehand, the reservoir team requested the use of SASMIc technology on Well A-P1.

10

A-P1

A-P2

A-P3

A-I1

10/10/2014

6



� The obtained results on well A-P1 were remarkable, as it showed that

the fault was in fact transmissible.

11

Tide Effects

Production begins

on well A-P3

Production begins

on well A-P2

Water Injection

begins on well A-I1

14 psi

scale


Field Case 1 – Conclusions

� Using the SASMIc technology, the reservoir team verified that the fault was in fact transmissible and the production and injection wells on both sides of the fault were connected.

� Since the data variation to capture this phenomena is in the order of 1 psi, the probability of detecting it during flow is very low.

� With this information, the simulation and geologic models were updated, and a well that was initially planed on being for water injection will now be drilled as a production well, for higher Recovery Factor.

12

10/10/2014

7


Contents


Campos Basin.


� Field Cases




13


� Reservoirs B and C, geographically near each other, were thought to be hydraulically isolated due to geological factors, since they are from different ages and have shale deposits between them.

� During a specific period of the field’s life, Reservoir B had all of it’s wells inoperable due to external factors.

� On that period, the field’s reservoir engineering team requested the SASMIctechnology on a static well of Reservoir B, while Reservoir C, beside it, was still active. The results follow:

Field Case 2 – Hydraulic Connections Between Reservoirs

14

B

C

10/10/2014

8


� SASMIc used for downhole data on Well B-I1, during 6 months:


15

Static (no flow) Downhole

Pressure on B-I1.

140 psi

scale

� Many other wells were analyzed during this period and the correlations were found with two water injection wells of Reservoir C, C-I1 and C-I2. In the next slide, a comparison is presented with this data and the injection flow rates of both wells.



Static (no flow) Downhole

Pressure on B-I1.

Flow rate on

Well C-I1.

Flow rate on

Well C-I2.

10/10/2014

9


Field Case 2 – Conclusions

17

� With no wells flowing on Reservoir B, it is possible to verify the

influence of nearby reservoirs, by monitoring the downhole data of a

static/shutdown well.

� It is noticed a clear influence of the water injection wells C-I1 and C-I2

on the region of well B-I1, even though they are in reservoirs of

different ages. This influence hadn’t been noticed before when both

reservoirs were in active production.

� With this information, the reservoir team will now plan a new

production well on Reservoir B, knowing that it can rely on pressure

support of the injection wells of Reservoir C. With this in mind, the

team can spare an injection well on Reservoir B, reducing costs on the

new project.


Conclusions and Recommendations

18

� With this technology, it is possible to retrieve information from wells

that are equipped with sensors but are not connected with the

platform (prior or post it’s main operation phase).

� Data retrieved on static condition are extremely valuable, since they

can bring new information that can only be measured in small scales.

� While this technology may not be available to all offshore scenarios,

the main objective of this paper is to highlight the importance of

retrieving well data in static conditions, especially prior to its initial

production, when the interference of the flow has not yet disturbed

the data analysis and important conclusions can be made concerning

the reservoir behavior.

10/10/2014

10

19

Thank you for your time.

Documents

REGIONAL ASSOCIATION OF OIL, GAS & BIOFUELS SECTOR ...media.arpel2011.clk.com.uy/rane/6/5CNametala.pdf · Permanent Downhole Gauges in Campos Basin Permanent Downhole Gauges provide