Abstract
Abstract
This paper addresses two questions for polymer flooding. First, what polymer solution viscosity should be injected? A base-case reservoir-engineering method is present for making that decision, which focuses on waterflood mobility ratios and the permeability contrast in the reservoir. However, some current field applications use injected polymer viscosities that deviate substantially from this methodology. At one end of the range, Canadian projects inject only 30-cp polymer solutions to displace 1000-3000-cp oil. Logic given to support this choice include (1) the mobility ratio in an unfavorable displacement is not as bad as indicated by the endpoint mobility ratio, (2) economics limit use of higher polymer concentrations, (3) some improvement in mobility ratio is better than a straight waterflood, (4) a belief that the polymer will provide a substantial residual resistance factor (permeability reduction), and (5) injectivity limits the allowable viscosity of the injected fluid. At the other end of the range, a project in Daqing, China, injected 150-300-cp polymer solutions to displace 10-cp oil. The primary reason given for this choice was a belief that high molecular weight viscoelastic HPAM polymers can reduce the residual oil saturation below that expected for a waterflood or for less viscous polymer floods. This paper will examine the validity of each of these beliefs.
The second question is: when should polymer injection be stopped or reduced? For existing polymer floods, this question is particularly relevant in the current low oil-price environment. Should these projects be switched to water injection immediately? Should the polymer concentration be reduced or graded? Should the polymer concentration stay the same but reduce the injection rate? These questions are discussed.
Cited by
16 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
1. Investigation of the Effect of Residual Oil and Wettability on Sulfonated Polymer Retention in Carbonate under High-Salinity Conditions;SPE Journal;2023-11-01
2. India's 1st Polymer Flood Scheme Implementation from Laboratory to Field in Heavy Oil Having Strong Aquifer;Day 3 Wed, October 04, 2023;2023-10-02
3. Learnings from the Planning and Execution of a Heavy Oil Polymer Flood Pilot in North Saskatchewan, Canada;Day 1 Wed, March 15, 2023;2023-03-10
4. Study of characteristics and adsorption of xanthan gum and polyacrylamide polymers in static systems, Jakarta, Indonesia;4TH INTERNATIONAL CONFERENCE ON EARTH SCIENCE, MINERAL AND ENERGY;2023
5. Simulation of Polymer Injection in Granular Media: Implications of Fluid-Driven Fractures, Water Quality, and Undissolved Polymers on Polymer Injectivity;SPE Journal;2022-09-19