Successful Field Pilot of In-Depth Colloidal Dispersion Gel (CDG) Technology in Daqing Oilfield
- Harry L. Chang (Intratech Inc.) | Xingguang Sui (Daqing Oilfield Co. Ltd.) | Long Xiao (Daqing Oilfield Co. Ltd.) | Zhidong Guo (Daqing Oilfield Co. Ltd.) | Yuming Yao (Daqing Oilfield Co. Ltd.) | Yuguo Yiao (Daqing Oilfield Co. Ltd.) | Gang Chen (Daqing Oilfield Co. Ltd.) | Kaoping Song (Daqing Petroleum Inst.) | James C. Mack (TIORCO Inc.)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- December 2006
- Document Type
- Journal Paper
- 664 - 673
- 2006. Society of Petroleum Engineers
- 5.4.7 Chemical Flooding Methods (e.g., Polymer, Solvent, Nitrogen, Immiscible CO2, Surfactant, Vapex), 7.3.3 Project Management, 2.4.3 Sand/Solids Control, 1.10.1 Drill string components and drilling tools (tubulars, jars, subs, stabilisers, reamers, etc), 5.7.2 Recovery Factors, 5.7.5 Economic Evaluations, 6.5.2 Water use, produced water discharge and disposal, 5.3.2 Multiphase Flow, 2.2.2 Perforating, 5.4.1 Waterflooding, 4.3.4 Scale
- 1 in the last 30 days
- 865 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 12.00|
|SPE Non-Member Price:||USD 35.00|
The first large-scale colloidal dispersion gel (CDG) pilot test was conducted in the largest oil field in China, Daqing oil field. The project was initiated in May 1999, and injection of chemical slugs was completed in May 2003.
This paper provides detailed descriptions of the gel-system characterization, chemical-slug optimization, project execution, performance analysis, injection facility design, and economics. The improvements of permeability variation and sweep efficiency were demonstrated by lower water cut, higher oil rate, improved injection profiles, and the increase of the total dissolved solids (TDS) in production wells.
The ultimate incremental oil recovery (defined as the amount of oil recovered above the projected waterflood recovery at 98% water cut) in the pilot area would be approximately 15% of the original oil in place (OOIP). The economic analysis showed that the chemical costs were approximately U.S. $2.72 per barrel of incremental oil recovered. Results are presented in 15 tables and 8 figures.
Achieving mobility control by increasing the injection fluid viscosity and achieving profile modification by adjusting the permeability variation in depth are two main methods of improving the sweep efficiency in highly heterogeneous and moderate viscous-oil reservoirs. In recent years (Wang et al. 1995, 2000, 2002; Guo et al. 2000), the addition of high-molecular-weight (MW) water-soluble polymers to injection water to increase viscosity has been applied successfully in the field on commercial scales. Weak gels, such as CDGs, formed with low-concentration polymers and small amounts of crosslinkers such as the trivalent cations aluminum (Al3+) and chromium (Cr3+) also have been applied successfully for in-depth profile modification (Fielding et al. 1994; Smith 1995; Smith and Mack 1997). Typical behaviors of CDGs and testing methods are given in the literature (Smith 1989; Ranganathan et al. 1997; Rocha et al. 1989; Seright 1994).
The giant Daqing oil field is located in the far northeast part of China. The majority of the reservoir belongs to a lacustrine sedimentary deposit with multiple intervals. The combination of heterogeneous sand layers [Dykstra-Parsons (1950) heterogeneity indices above 0.5], medium oil viscosities (9 to 11 cp), mild reservoir temperatures (~45°C), and low-salinity reservoir brines [5,000 to 7,000 parts per million (ppm)] makes it a good candidate for chemical enhanced-oil-recovery processes.
Daqing has successfully implemented commercial-scale polymer flooding (PF) since the early 1990s (Chang et al. 2006). Because the PF process is designed primarily to improve the mobility ratio (Chang 1978), additional oil may be recovered by using weak gels to further improve the vertical sweep. Along with the successes of PF in the Daqing oil field, two undesirable results were also observed: (1) high concentrations of polymer produced in production wells owing to the injection of large amounts of polymer (~1000 ppm and 50% pore volume) and (2) the fast decline in oil rates and increase in water cuts after polymer injection was terminated.
In 1997, a joint laboratory study between the Daqing oil field and Tiorco Inc. was conducted to investigate the potential of using the CDG process, or the CDG process with PF, to further improve the recovery efficiency, lower the polymer production in producing wells, and prolong the flood life.
The joint laboratory study was completed in 1998 with encouraging results (Smith et al. 2000). Additional laboratory studies to further characterize the CDG gellation process, optimize the formulation, and investigate the degradation mechanisms were conducted in the Daqing field laboratories before the pilot test. A simplistic model was used to optimize the slug designs and predict incremental oil recovery. Initial designs called for a 25% pore volume (Vp ) CDG slug with 700 ppm polymer and the polymer-to-crosslinker ratio (P/X) of 20 in a single inverted five-spot patten. Predicted incremental recovery was approximately 9% of OOIP.
|File Size||1 MB||Number of Pages||10|
Chang, H.L. 1978. Polymer Flooding Technology Yesterday,Today, and Tomorrow. JPT 30 (8): 1113-1128. SPE-7043-PA. DOI:10.2118/7043-PA.
Chang, H.L., Zhang, Q.G., and Wang, Q.M.2006. Advances in Polymer Floodingand Alkaline/Surfactant/
Polymer Processes as Developed and Applied in the People's Republic ofChina. JPT 58 (2): 84-89. SPE-89175-MS. DOI:10.2118/89175-MS.
DeMarco, M. 1969. Simplified MethodPinpoints Injection Well Problems. World Oil (April 1969) 97.
Dykstra, H., and Parsons, R.L. 1950. ThePrediction of Oil Recovery by Waterflood. Secondary Recovery of Oil inU.S.,160. Washington, DC:API.
Fielding, R.C. Jr., Gibbons, D.H., andLegrand, F.P. 1994. In-Depth DriveFluid Diversion Using an Evolution of Colloidal Dispersion Gels and New BulkGels: An Operational Case History of North Rainbow Ranch Unit. Paper SPE27773 presented at the SPE/DOE Symposium on Improved Oil Recovery, Tulsa, 17-20April. DOI: 10.2118/27773-MS.
Guo, W., Cheng, J., Yao, Y. et al. 2000.Commercial Pilot Test of PolymerFlooding in Daqing Oil Field. Paper SPE 59275 presented at the SPE/DOEImproved Oil Recovery Symposium, Tulsa, 3-5 April. DOI:10.2118/59275-MS.
Hall, H.N. 1963. How to Analyze WaterloodInjection Well Performance. World Oil (October 1963) 128.
Moffitt, P.D. and Menzie, D.E. 1978. Well Injection Tests of Non-NewtonianFluids. Paper SPE 7177 presented at the 1978 Rocky Mountain RegionalMeeting, Cody, Wyoming, 17-19 May. DOI: 10.2118/7177-MS.
Ranganathan, R., Lewis, R., McCool, C.S.,Green, D.W., and Willhite, G.P. 1997. An Experimental Study of the In-SituGelation Behavior of a Polyacrylamide/Aluminum Citrate "Colloidal DispersionGel" in a Porous Medium and its Aggregate Growth During Gelation Reaction.Paper SPE 37220 presented at the International Symposium on Oilfield Chemistry,Houston, 18-21 February. DOI: 10.2118/37220-MS.
Rocha, C.A., Green, D.W., Willhite, G.P.,and Michnick, M.J. 1989. AnExperimental Study of the Interactions of Aluminum Citrate Solutions and SilicaSand. Paper SPE 18503 presented at the SPE International Symposium onOilfield Chemistry, Houston, 8-10 February. DOI: 10.2118/18503-MS.
Seright, R.S. 1994. Propagation of anAluminum-Citrate-HPAM Colloidal-Dispersion Gel Through Berea Sandstone. PRRC94-29 (June 1994), New Mexico Petroleum Recovery Research Center.
Smith, J.E. 1989. The Transition Pressure: A QuickMethod for Quantifying Polyacrylamide Gel Strength. Paper SPE 18739presented at the SPE International Symposium on Oilfield Chemistry, Houston,8-10 February. DOI: 10.2118/18739-MS.
Smith, J.E. 1995. Performance of 18 Polymers inAluminum Citrate Colloidal Dispersion Gels. Paper SPE 28989 presented atthe SPE International Symposium on Oilfield Chemistry, San Antonio, Texas,14-17 February. DOI: 10.2118/28989-MS.
Smith, J.E. and Mack, J.C. 1997. GelsCorrect In-Depth Reservoir Permeability Variation. Oil & Gas J. (6January 1997).
Smith, J.E., Liu, H., and Guo, Z.D. 2000.Laboratory Studies of In-DepthColloidal Dispersion Gel Technology for Daqing Oil Field. Paper SPE 62610presented at the 2000 SPE/AAPG Western Regional Meeting, Long Beach,California, 19-22 June. DOI: 10.2118/62610-MS.
Wang, D., Cheng, J., Wu, J., and Wang, G.2002. Experiences Learned AfterProduction of More Than 300 million Barrels of Oil by Polymer Flooding inDaqing Oil Field. Paper SPE 77693 presented at the SPE Annual TechnicalConference and Exhibition, San Antonio, Texas, 29 September-2 October. DOI:10.2118/77693-MS.
Wang, D., Li, Q., Gong, X., and Wang, Y.2000. The Engineering andTechnical Aspects of Polymer Flooding in Daqing Oil Field. Paper SPE 64722presented at the SPE International Oil and Gas Conference and Exhibition inChina, Beijing, 7-10 November. DOI: 10.2118/64722-MS.
Wang, D., Zhang, J., Meng, F. et al.1995. Commercial Test of PolymerFlooding in Daqing Oil Field, Daqing Petroleum Administrative Bureau. PaperSPE 29902 presented at the International Meeting on Petroleum Engineering,Beijing, 14-17 November. DOI: 10.2118/29902-MS.