Horizontal Completion Design and Work Overs

Heavy Oil Recovery

IntroductionHeavy oil’s viscosity is the property which is usually reduced to allow fluids to flow and be produced. Thermal methods are employed however they required special well considerations because of the high temperature they face. Well considerations are:• Drilling stable boreholes & accurately landing horizontal

wells• Designing tubular systems • Using durable cements • Installing sand control,• Completion and artificial lift equipment

Scope of Presentation

• Heavy Oil Recovery Techniques• Benefits of Horizontal Wells• Casing & Tubing• Cementing• Sand Control• Artificial Lift• Workovers• Advancements in Completion Equipment• Feasibility of Horizontal Completions & Workovers in

Trinidad• Conclusion/Recommendations

Heavy Oil Recovery Techniques

Open Pit Mining

Non-Mining

Thermal

CSS

SAGD

THAI

Chemical

VAPEX

Non-Thermal

CHOPS

PPT

MEOR

Benefits of Horizontal Wells?

Benefits include:• Horizontal makes more efficient use of reservoir

pressure• Thin low permeability reservoirs• Layered formations• Partially depleted and flooded reservoirs can be more

effectively drained• Horizontal can produce at higher rates at similar

drawdown or similar rate at lower drawdown• Horizontal delays coning (cresting) in case of bottom

water drive reservoir

Horizontal Completions

The most important aspects of completions for thermal heavy oil wells either injection wells or production wells are:

• Casing & Tubing design • Cementing • Sand control• Artificial Lift

Casing & Tubing

• Higher Strength Casing• Insulated Tubing• Thermal Tubing Packer• Thermal Wellhead• Centralizers• Pre tensioned Casing• Casing threading

Cementing

• Centralizers• Cement with high concentrations of Silica flour

& Alumina.• Good cement practices

Sand Control

• Stand-alone Screens• Slotted Liners• Pre-packed Screens• Wire Wrapped Screens• Premium Screens• Gravel Packing

• Reciprocating Rod Lift Systems• Progressing Cavity Pumping Systems• Electric Submersible Pumping Systems• Hydraulic Lift Systems

Artificial Lift

WorkoversOf all the problems that can occur during production, three stand out the most: equipment failure, wellbore problems, and saltwater disposal.

There are 4 different types of workovers and they are caused by:

• Mechanical Problems• Well Blockage• Near Field Problems• Far Field Problems

Advancements in Completion Equipment

• Schlumberger - The REDA Hotline high-temperature ESP system

• SCI Construction Materials Group - White High Alumina Cement (WHAC)

• Schlumberger – OptiPac Alternate Path Screens

• Schlumberger - MRP Modular Retrievable Packer for ESP Completions

Feasibility in Trinidad

• Excellent for thin bedded pay zones• Excellent technical skills in directional drilling• Productivity enhancement (as much as 10 to 20 fold

higher)• Fewer wells per section• Fewer gathering systems• Better well monitoring & hence better reservoir

management• Longer well life & less Workovers• Good sand control available for Trinidad’s

unconsolidated sandstone reservoirs

Conclusion/Recommendations

• Productivity of horizontal wells is 3–4 times that of vertical wells.

• Added benefit of having to drill less wells to produce a reservoir.

• Used where the vertical well normally cannot be drilled. • Using the combination of horizontal and vertical wells can

greatly improve recovery.• Makes more efficient use of reservoir pressure.• Delays coning (cresting) in case of bottom water drive

reservoir.• Most EOR methods require the use of horizontal

completions.

ReferencesBooks

• Ali, Farouq S.M.1997.Practical Heavy Oil Recovery, first edition, Edmonton, Alberta, Canada, • Journals• Beakley, W.B. 1965. The Hardware of Steam Injection. Paper 65-006: 9-13

Papers• Joshi, S.D. 2003. Cost/Benefits of Horizontal Wells. Paper SPE 83621 presented at the SPE Regional AAPG

Pacific Section Joint Meeting, California, U.S.A, 19-24 May.• Brunnings, C. 2005. New Completion Developments for the production of Heavy and Extra-Heavy Oil in

Eastern Venezuela. Paper SPE/PS-CIM/CHOA 97914 presented at SPE International Thermal Operations and Heavy Oil Symposium Held in Calgary, Alberta, Canada, 1-3 November.

• Bianco, L.C. et al. 2006. Challenges on Completion for Productivity for Deepwater Heavy Oil. Paper SPE 9342 presented at SPE International Symposium and Exhibition on Formation Damage Control held in Lafayette, L.A, 15-17 Febuary.

• Martins, A.L. 2009. Sand Control in Long Horizontal Section Wells. Paper OTC 20113 presented at the Offshore Technology Conference held in Houston, Texas, U.S.A, 4-7 May.

• Cunha, L.B. 2005. Recent In-Situ Oil Recovery Technologies for Heavy and Extra-heavy Oil Reserves. Paper SPE 94986 presented at SPE Latin America and Caribbean Petroleum Engineering Conference held in Rio de Janeiro, Brazil, 20-23 June.