Downhole Water Sink (DWS) Completion Enchance OIL Recovery in Reservoirs with Water Coning Problem

1999 ◽  
Author(s):  
A.K. Wojtanowicz ◽  
E.I. Shirman ◽  
H. Kurban
Keyword(s):  
Oil Recovery ◽  
Water Coning ◽  
Downhole Water Sink

Inflow Performance and Pressure Interference in Dual-Completed Wells With Water Coning Control

2002 ◽  
Vol 124 (4) ◽  
pp. 253-261 ◽  
Author(s):  
Andrew K. Wojtanowicz ◽  
Ephim I. Shirman
Keyword(s):  
Three Dimensional ◽  
Maximum Pressure ◽  
Water Drainage ◽  
Two Phase ◽  
Drainage Rate ◽  
Water Coning ◽  
Water Cut ◽  
Downhole Water Sink ◽  
Inflow Performance ◽  
Well Completions

Dual-completed wells with Downhole Water Sink (DWS) are used for water coning control in oil reservoirs with bottom water drive. In DWS wells, the second (bottom) completion—placed in the water column—is used for draining water. This prevents the water cone invasion and allows free oil inflow in the top completion. The decision on using DWS or a conventional (single-completed) well is based upon deliverability comparison of the two wells. This paper shows how to describe DWS well deliverability in terms of the top and bottom production rates, water cut, and pressure drawdown. Also, the effect of pressure interference between two well completions on deliverability limits has been studied and qualified experimentally. DWS well deliverability depends on two variables, pressure drawdown and water drainage rate, and is described by a three-dimensional Inflow Performance Domain (IPD). Visual-Basic software based on a new analytical model of IPD has been developed to calculate critical (fluid breakthrough) rates for oil and water. The critical rates identify inflow conditions to the well’s completions—single or two-phase inflow. Also calculated are the values of water cut and maximum pressure drawdown at the well. An example demonstrates the procedure and a complete IPD plot. The experimental study, using a Hele-Shaw physical model of DWS well, demonstrates the reduction of well’s deliverability caused by pressure interference from the second (bottom) completion. The experiments have shown, however, that the deliverability decrease is small and over-compensated by the increase of oil rate due to simultaneous reduction of water cut.

scholarly journals The effect of chemically enhanced oil recovery on thin oil rim reservoirs

2021 ◽  
Vol 11 (3) ◽  
pp. 1461-1474
Author(s):  
O. A. Olabode ◽  
V. O. Ogbebor ◽  
E. O. Onyeka ◽  
B. C. Felix
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Niger Delta ◽  
Surfactant Concentration ◽  
Base Case ◽  
Production Studies ◽  
Water Alternating Gas ◽  
Water Coning ◽  
Oil Rim

AbstractOil rim reservoirs are characterised with a small thickness relative to their overlying gas caps and underlying aquifers and the development these reservoirs are planned very carefully in order to avoid gas and water coning and maximise oil production. Studies have shown low oil recoveries from water and gas injection, and while foam and water alternating gas injections resulted in positive recoveries, it is viewed that an option of an application of chemical enhanced oil recovery option would be preferable. This paper focuses on the application of chemical enhanced oil recovery to improve production from an oil rim reservoir in Niger Delta. Using Eclipse black oil simulator, the effects of surfactant concentration and injection time and surfactant alternating gas are studied on overall oil recovery. Surfactant injections at start and middle of production resulted in a 3.7 MMstb and 3.6 MMstb at surfactant concentration of 1% vol, respectively. This amounted to a 6.6% and 6.5% increment over the base case of no injection. A case study of surfactant alternating gas at the middle of production gave an oil recovery estimate of 10.7%.

A Theoretical and Experimental Coning Study

1975 ◽  
Vol 15 (03) ◽  
pp. 247-254 ◽  
Author(s):  
N. Mungan
Keyword(s):  
Experimental Study ◽  
Numerical Model ◽  
Production Rate ◽  
Oil Recovery ◽  
Symmetry Plane ◽  
Radial Symmetry ◽  
Bottom Plate ◽  
Vertical Permeability ◽  
Water Coning ◽  
Horizontal Permeability

Abstract Experimental and numerical studies were made of water coning in an oil-producing well under two-phase, immiscible, incompressible flow. The model chosen was a pie-shaped, cylindrical sand pack with radial symmetry. Saturations were measured in situ by 70 micro-resistivity probes embedded in the sand pack. Results indicated that the numerical model pack. Results indicated that the numerical model simulated the experiments adequately. Increasing the production rate or the wellbore penetration lead to earlier water breakthrough; however, oil recovery was independent of production rate. As the ratio of gravity to viscous forces increased, the oil recovery at any given WOR became greater; wells should have been spaced closer if the horizontal permeability was low or if the vertical permeability permeability was low or if the vertical permeability was high. High vertical permeability decreased the oil recovery, while the opposite was true for horizontal permeability. In stratified formations, the highest permeability. In stratified formations, the highest oil recovery resulted when the most permeable section was located near the top of the oil-bearing zone. Introduction Coning in oil-producing wells is a problem more common than generally is believed. It occurs in producing formations that are underlain by water, producing formations that are underlain by water, overlain by gas, where a secondary gas cap develops, or are under the conditions of water, gas, or solvent injection. The present oil shortage has resulted in wells being produced at full capacity -- a situation that aggravates coning. Under severe coning conditions, well allowables must be reduced to. a level that minimizes coning and avoids loss of ultimate oil recovery. These considerations make study of the coning phenomenon more important than previously. previously.The two objectives a this study wereto apply a numerical coning model to actual laboratory results to verify validity of the numerical model, andto use the numerical model to study the effect of certain parameters on development of be cone and on the oil-recovery performance. The study was restricted to water coning in oil wells in a reservoir system of cylindrical geometry with radial symmetry. PROCEDURE PROCEDURE SELECTION OF A NUMERICAL MODEL The Blair and Weinaug problem was solved using four different numerical coning models and the solutions obtained were compared with the results of Letkeman and Ridings to select the numerical model to be used in the rest of the study. EXPERIMENTAL STUDY For the experimental study, a pie-shaped, cylindrical coning model was constructed of clear plexiglass. The model was 16 in. high and had a plexiglass. The model was 16 in. high and had a radius of 20 in. and an angle of 30 degrees. It was constructed of 1-in.-thick plexiglass and was supported by a metal frame all around to avoid bulging during flow. To distribute the injected water uniformly across the bottom face of the sand pack, the bottom plate had fluid grooves that were pack, the bottom plate had fluid grooves that were overlain by several layers of 325-mesh monel screen. Seventy micro-resistivity probes were constructed and positioned inside the model for measuring the electrical resistivity. Probes were constructed from two 1/8-in.-square, 100-mesh monel screens positioned parallel to one another and separated by positioned parallel to one another and separated by about 1/4 in. A thin, insulated wire led from each screen through a hole drilled in the side plates of the model to an electrical 70-point junction box, and from there to a specially constructed 70-channel scanner. The scanner could scan any or all of the resistivity probes at a rate ranging from 112 to 60 seconds per probe. A timer permitted continuous scanning or time-lapse scanning ranging from once per hour to once every 8 hours. The output of the per hour to once every 8 hours. The output of the scanner was put through a digital voltmeter to a digital recorder. During a flow experiment, the resistivity at each probe thus could be measured and recorded automatically. The resistivity probes were positioned. on a central symmetry plane, thus permitting measurements far from the boundaries of the model. SPEJ P. 247

A Depletion Strategy for an Active Bottom-Water Drive Reservoir Using Analytical and Numerical Models—Field Case Study

2009 ◽  
Vol 131 (10) ◽  
Author(s):  
Ibrahim Sami Nashawi ◽  
Ealian H. Al-Anzi ◽  
Yousef S. Hashem
Keyword(s):  
Production Rate ◽  
Oil Recovery ◽  
Bottom Water ◽  
Numerical Models ◽  
Water Production ◽  
Breakthrough Time ◽  
Well Completion ◽  
Water Breakthrough ◽  
Water Coning ◽  
Single Well

Water coning is one of the most serious problems encountered in active bottom-water drive reservoir. It increases the cost of production operations, reduces the efficiency of the depletion mechanism, and decreases the overall oil recovery. Therefore, preventive measures to curtail water coning damaging effects should be well delineated at the early stages of reservoir depletion. Production rate, mobility ratio, well completion design, and reservoir anisotropy are few of the major parameters influencing and promoting water coning. The objective of this paper is to develop a depletion strategy for an active bottom-water drive reservoir that would improve oil recovery, reduce water production due to coning, delay water breakthrough time, and pre-identify wells that are candidates to excessive water production. The proposed depletion strategy does not only take into consideration the reservoir conditions, but also the currently available surface production facilities and future development plan. Analytical methods are first used to obtain preliminary estimates of critical production rate and water breakthrough time, then comprehensive numerical investigation of the relevant parameters affecting water coning behavior is conducted using a single well 3D radial reservoir simulation model.

First Autonomous Inflow Control Device AICD Deployment in Wassana Field

2021 ◽  
Author(s):  
Pongpak Taksaudom ◽  
Tim Kelly ◽  
Atisuda Meeteerawat ◽  
David Carter ◽  
Kannappan Swaminathan ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Oil Recovery ◽  
High Water ◽  
Oil Field ◽  
Water Production ◽  
Oil Viscosity ◽  
Initial Development ◽  
Water Handling ◽  
Water Breakthrough ◽  
Water Coning

Abstract Wassana oil field is located in the Gulf of Thailand with shallow water depth at approximately 60m. A major challenge is excessive water production which reduces reserves recovery and increases costs associated with produced water handling. The target reservoir is ~20ft thick with active aquifer support. The low oil/ water mobility ratio due to high oil viscosity (≥ 30cp) risks early water coning and high watercuts. All horizontal wells drilled in the Wassana field during the initial development and the first infill campaign were completed as non-ICD openhole standalone screen. For the second infill campaign, the non-ICD simulation showed water breakthrough occurring at the start of production. Once breakthrough occurs, water production rapidly dominates production prompting premature shut-in of production, leaving much unrecovered oil behind. To overcome this problem, Autonomous Inflow Control Devices (AICDs) were introduced to control the production influx profile across the entire horizontal section to delay water coning and to significantly choke back water production when it occurs. With intensive pre-drilled AICD modeling using 3D dynamic time lapse simulation, two wells in the second infill campaign were subsequently chosen to be completed with a configuration of zonal AICDs isolated by swell packers. This design enables isolation across horizontal reservoir section with high water production in tandem with compartmentalization across the contrasting permeability region. Once water breakthrough occurs, the unique autonomous ability of the cyclonic AICD is triggered by exploiting the physics of rotational flow of the vortex-inducing pressure drop principle through a restrictive funnel-type flow-path in a tool with no moving parts. The low viscosity of both water and gas phase promotes higher rotational velocity inducing higher pressure drop or back-pressure of inflow vortex breakdown towards the inlet into the tubing flow, thus helping to further reduce the influx contribution of the high water producing sections. Essentially, the higher watercut zones flowing through the device is restricted more rigorously compared to the oil-prone zones. Both wells were successfully drilled and completed with AICDs in February 2019. Based on actual and early-production history-matched performance, these 2 pilot AICD wells are projecting an improved cumulative oil production gain of up to +7% over 5 years of production. The reduction or delay of water production can benefit the field both in enhancing oil recovery and water handling cost saving.

Vertical Interference Test in Wells With Downhole Water Sink Completions

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Ephim Shirman ◽  
Andrew Wojtanowicz
Keyword(s):  
Analysis Method ◽  
Type Curves ◽  
Two Fluids ◽  
Testing Method ◽  
Water Coning ◽  
Interference Test ◽  
Permeability Anisotropy ◽  
Downhole Water Sink ◽  
Well Completions ◽  
Vertical Interference Test

Downhole water sink (DWS) well completions segregate production in the wellbore by producing water from the underlying aquifer and oil—from the oil zone of the reservoir. A pump drains water from the bottom completion to create a pressure drawdown that prevents water from coning up to the top, oil producing zone. Successful application of DWS technology in wells with water-coning problem requires effective isolation between the top and bottom completions of the well. Since DWS technology requires dual completion, the completion is configured for vertical interference testing. The problem is that such test involves flow of two fluids, water and oil. This paper presents a new mathematical model and analysis method for vertical interference testing using top completion (in the oil leg) for production and bottom completion (in the water leg) for observation. The model is analytical and accommodates partial penetration and permeability anisotropy. The analysis method employs a family of type-curves. Examples of possible applications of this new testing method are also shown in this paper.

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