Cyclic Water Injection: Improved Oil Recovery at Zero Cost

Surguchev, L.M.; Koundin, Alexander; Melberg, O. B.; Menard, Wendell P.

doi:10.3997/2214-4609.201406331

Cited by 4 publications

(6 citation statements)

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“…According to Surguchev (2002), reservoirs that would most benefit from cyclic waterflooding should have the following characteristics:…”

Section: Cyclic Injection Backgroundmentioning

confidence: 99%

“…In a water-wet reservoir, the imbibition of water in a zone with high oil saturation is accelerated during pressure increase, i.e. Water flow capacity from the low permeable zone during the depressurizing half-cycle is limited by (a) the relative permeability to water at low water saturation; (b) the capillary pressure in water-wet rock (Surguchev, 2002). Acceleration of the imbibition and fluid redistribution which is caused by cross-flow happening between zones of high and low oil saturation is a goal of this process, thus releasing and displacing additional oil from the previously non-swept regions.…”

Section: Cyclic Injection Backgroundmentioning

confidence: 99%

“…The derived analytical solution allows one to estimate cross-flow in a layered reservoir subjected to a periodic variation in time of the pressure and it accounts for the compressibility effects (Surguchev, 2002). The basic assumption is that the total thickness is small compared to the total length of the reservoir and that the porosities and compressibilities of the layers, viscosities of the fluids, are constant.…”

Section: Cyclic Injection Backgroundmentioning

confidence: 99%

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Investigation of Cyclic Water Injection after Polymer Flood in Xing4-6 Field, Daqing

Gao

Feng

Zhang³

et al. 2009

All Days

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Xing 4-6 is a multilayer sandstone reservoir which has already experienced a secondary water flood in the entire reservoir and a tertiary polymer injection in certain formations. The polymer flooding began in 2001 as a typical polymer flooding field in Daqing. Currently, the Xing 4-6 is reaching the end of the designed polymer injection. In this paper, a cyclic water flood after the polymer injection is investigated in this field. The research is principally on the basis of reservoir simulations. After the history matching of the water flooding, a polymer flooding model describing target polymer flooding layer was extracted from the water flooding model to simulate the polymer injection process. By combining the development information and simulation results, the efficiency of the polymer flood was analyzed as the fundamental of cyclic injection investigation. Based on the plenty of geological study and multidisciplinary investigation, a cyclic flooding model describing Putaohua I formation was established. Two cyclic injection cases were designed. Two cyclic units were defined in the model: the priority payzone P I3 3 was considered as an independent cyclic unit due to its considerable proportion of the original oil in place (OOIP); other six layers were set as the second unit. In one case, the cyclic water was only conducted in the first unit; the other unit still employed continuous water injection. In the other case, two units were alternatingly involved in the cyclic injection. The predictions showed that the vertical sweep efficiency had been improved in upper zones which have vertical connectivity with lower layers due to the pressure pulsation and capillary pumping of the wetting phase in the low-permeability zones, especially the zones with high heterogeneities. Areally, the dead oils which were formed by the un-improvement of injection and production system were also mobilized. The cyclic water injection after polymer flooding improved the ultimate recovery. One more significant advantage was the extended use of the current well pattern. Comparing two cases, the case with only one cyclic unit involved had a better development efficiency in the priority payzone P I3 3 than that of the case with alternating cyclic injection, the incremental recovery in P I3 3 was 1.21%, which was 0.37% higher than that of the alternating case. Because the case with alternating cyclic injection took all zones into the consideration, the entire flooding efficiency was better than the other. The incremental recovery of alternating cyclic injection was 0.84% which was 0.32% higher than that of one cyclic unit injection on the reservoir scale. The detailed analysis in each case was also presented.

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“…According to Surguchev (2002), reservoirs that would most benefit from cyclic waterflooding should have the following characteristics:…”

Section: Cyclic Injection Backgroundmentioning

confidence: 99%

Section: Cyclic Injection Backgroundmentioning

confidence: 99%

Section: Cyclic Injection Backgroundmentioning

confidence: 99%

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Investigation of Cyclic Water Injection after Polymer Flood in Xing4-6 Field, Daqing

Gao

Feng

Zhang³

et al. 2009

All Days

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“…According to Surguchev et al, 1 and Alvarez et al 6 , some features that favor CWI are: Hysterisis of the capillary and relative permeability curves at the micro-level, signifying that during pulsing, oil, water and gas effectively flow switching between imbibition and drainage, and vice versa, as pressure differences increase or decrease or even reverse sign.…”

Section: Cwi Recovery Mechanismsmentioning

confidence: 99%

“…In this sense, Cyclic Water Injection (CWI) has been proposed as alternative for waterflooding optimization in fractured or heterogeneous reservoirs 1 . In production areas where waterflooding facilities are available, life extension of these projects by means of well-conformance or pattern re-arrangement become desirable to delay investments or better yet allow companies the time to deploy other IOR strategies.…”

Section: Introductionmentioning

confidence: 99%

Cyclic Water Injection Simulations for Evaluations of its Potential in Lagocinco Field

Stirpe

Guzmán

Manrique³

et al. 2004

SPE/DOE Symposium on Improved Oil Recovery

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TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractCyclic Water Injection (CWI) has been proposed as a technique to improve water sweep in stratified and fractured reservoirs. This recovery process takes advantage of the pressure transient response in regions of different permeability, leading to forced imbibition of the lesser permeable layers, in the case of stratified reservoirs. A process such as this is expected to yield an additional recovery between 2 and 7% over continuous waterflooding and a significant reduction in watercut, reason why it has been proposed as a zero cost EOR process, wherever facilities for water injection are already available. Several mechanisms have been attributed the additional oil production, among which are listed pressure differences between layers with limited communication and hysterisis of the capillary pressure and relative permeability curves. Here we have taken a fullfield model of an extensively investigated reservoir of Western Venezuela, the VLE-305, located in the Lagocinco field to analyze some of the critical variables of the process and determine the potential for cyclic water flooding. The reservoir has been proposed as a candidate for immiscible WAG injection and a successful pilot test has been carried out. This deep, stratified sandstone reservoir meets the characteristics sought in cyclic water injection projects. In recent work, it was shown that some potential exists for water cyclic injection in the WAG pilot area. Production history of the field has been used to help with the analysis of critical variables of this process, including injector-to-producer well distance and reservoir pressure relative to the bubble point pressure, among others. Additionally, a recently developed analytical model of the process was also tested to determine its potential as a fast evaluation tool for CWI. Results show that permeability trends, reservoir pressure, well distance and water saturation at the startup of the process have high impact on the potential additional recovery, leading to recommendations for the application schedule of the process.

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Improved Oil Recovery by Cyclic Injection and Production

2008

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Cyclic waterflooding is an IOR-method that improves oil production in heterogeneous reservoirs with high-permeability contrast. The concept of the method is based on pulsed injection and alternating of waterflood patterns. The main effect induced by the cycling of wells is oil production increase accompanied by water production decrease. The production increase is achieved by improved sweep efficiency in low permeable zones of a reservoir non swept by traditional waterflooding process. The cyclic water injection process was successfully applied in a number of sandstone and carbonate oil fields in Russia, USA and China. The important advantages of the method are virtually zero additional cost and simple implementation procedure. The uncertainty with the method is related to understanding the IOR mechanism, ability to accurately model the process and design a field application. The paper presents the results of the study of cyclic water injection and oil production at a North Sea heterogeneous sandstone reservoir. The study consists of the field history analysis, pre-screening cyclic efficiency estimation and numerical reservoir simulation to design the field application of the IOR-method. The field history analysis shows the presence of cycles in injection and production and their influence on water-cut change. Pre-screening analytical tool was used to perform a wide-range sensitivity analysis with respect to rock-fluid parameters, heterogeneity, cycle length and pressure conditions in order to understand the mechanism and to estimate the IOR potential. Finally the sector model reservoir simulation was used to optimize the cyclic process by alternating the waterflood patterns and to design the field application. The simulations show decrease of water production and improvement of oil production by up to 3% with short time and by 5% with long time cycles. Introduction The cyclic waterflooding improves sweep efficiency in heterogeneous reservoirs. In the IOR-method a combination of two processes of (1) pulsed injection (production) and (2) alternating of waterflood patterns is used. The cyclic waterflooding was successfully applied in a number of sandstone and carbonate oil fields in USA1,2 and Former Soviet Union 3,4,5. The cyclic injection potential was evaluated in a number of studies 3,4,5,6,7,8. Analytical estimation and numerical simulations have shown significant potential with oil production increase by up to 10% and reduction of water-cut by up to 20%. Recent experimental studies 9 have demonstrated improvement of oil recovery under pulsed pressure conditions at laboratory scale. The uncertainty of cyclic waterflooding is related to understanding of the IOR mechanism, ability to model and predict efficiency of the process, and to design a field application for specific reservoir conditions. In this paper we analyze production and injection data, discuss and evaluate parameters that affect cyclic waterflooding, estimate efficiency of the method for different scenarios of field application. Cycling effects which occurred in the production history of a heterogeneous sandstone reservoir were analyzed to evaluate their influence on water-cut behavior. The analytical tool 8,10 was used for screening of the cyclic injection. A wide range sensitivity analysis was performed to estimate efficiency of the cyclic process. Based on the analytical screening results the numerical simulations of cyclic waterflooding were carried out on a sector reservoir model. IOR potential of cyclic reallocation of water injection volumes between well patterns was also estimated.

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Cyclic Water Injection: Improved Oil Recovery at Zero Cost

Cited by 4 publications

References 0 publications

Investigation of Cyclic Water Injection after Polymer Flood in Xing4-6 Field, Daqing

Investigation of Cyclic Water Injection after Polymer Flood in Xing4-6 Field, Daqing

Cyclic Water Injection Simulations for Evaluations of its Potential in Lagocinco Field

Improved Oil Recovery by Cyclic Injection and Production

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