迟杰,鞠斌山,付庆杰
CHI Jie,JU Binshan,FU Qingjie

• 1:中国地质大学(北京)能源学院

摘要(Abstract)：

极限井距计算方法对于特低渗透油藏确定合理井网密度具有重要意义。考虑CO_2对原油的降黏作用及油相启动压力梯度的变化,建立了一维两相渗流数学模型,并应用特征线法、试算法和迭代法进行求解,推导出特低渗透油藏CO_2非混相驱极限井距计算方法。同时开发了极限井距计算软件进行井距实例计算,绘制了理论图版。结果表明:CO_2对于原油的降黏作用可达到60%以上,油相黏度自注气端至采出端逐渐增大;生产压差为10~20 MPa,注气速度分别为10、15、20、25、30 t/d的极限井距均比未考虑油相黏度及油相启动压力梯度变化的极限井距大;极限井距随生产压差增大而增大,随注气速度、地层原油黏度、CO_2黏度增大而减小;生产压差相同时,注采两端压力越大,极限井距越大,油相黏度及油相启动压力梯度的下降幅度越大。
The computing method of the critical well spacing possesses the vital significance for determining the reasonable well spacing density in ultra-low permeability reservoirs. A one-dimensional two-phase mathematical model was established considering the visbreaking action of CO_2 in the crude oil and the changes of the threshold pressure gradient,and moreover with the help of the solutions by characteristic linear method,trial-and-error method and iterative method,the calculating method was deduced for the critical well spacing of CO_2 immiscible flooding in ultra-low permeability reservoirs. At the same time,the calculating software for the critical well spacing was developed and furthermore practiced,and then the theoretical board chart was drawn as well. The results show that when the visbreaking action is more than 60%,the viscosity of the oil phase gradually increases from the gas injected end to produced one; the critical well spacing is greater for the ones with 10-20 MPa production pressure differential and gas injection rates are 10,15,20,25,30 t/d respectively comparing with the ones whose oil phase viscosities and threshold pressure gradients are not considered; with the rise of the producing pressure differential,the critical well spacing is enlarged as well,while it is reduced with the increases of the gas injection rate,reservoir oil viscosity and CO_2viscosity; when the producing pressure differential is same,the greater the pressures at both ends,the larger the critical well spacing will be,so are the reduced degree for the oil viscosity and starting pressure gradient.

关键词(KeyWords)： 特低渗透油藏;非混相驱;极限井距;油相启动压力梯度;非活塞驱替;降黏
ultra-low permeability oil reservoir;immiscible flooding;critical well spacing;oil-phase threshold pressure gradient;non-piston displacement;viscosity reduction

Abstract:

Keywords:

基金项目(Foundation): 中央高校基本科研业务费专项基金项目(2652015142)

作者(Author): 迟杰,鞠斌山,付庆杰
CHI Jie,JU Binshan,FU Qingjie

参考文献(References)：

• [1]李道品.低渗透砂岩油田开发[M].北京:石油工业出版社,1997:4-6.
• [2]吴柏志.低渗透油藏高效开发理论与应用[M].北京:石油工业出版社,2009.
• [3]李忠兴,韩洪宝,程林松,等.特低渗油藏启动压力梯度新的求解方法及应用[J].石油勘探与开发,2004,31(3):107-109.
• [4]Holm L W.Evolution of the Carbon Dioxide Flooding Processes[J].Journal of Petroleum Technology,1987,39(11):1337-1342.
• [5]Martin D F,Taber J J.Carbon Dioxide Flooding[J].Journal of Petroleum Technology,1992,44(4):396-400.
• [6]Mungan N.Carbon Dioxide Flooding-Fundamentals[J].The Journal of Canadian Petroleum,1981,20(2):87-92.
• [7]Prosper G,Ali S F.Scaled Model Studies Of The Immiscible Carbon Dioxide Flooding Process At Low Pressures[J].Petroleum Society of CIM and AOSTRA,1991,2(2):1-15.
• [8]Mungan N.Carbon Dioxide Flooding As An Enhanced Oil Recovery Process[J].Journal of Canadian Petroleum Technology,1992,31(9):13-15.
• [9]王端平,时佃海,李相远,等.低渗透砂岩油藏开发主要矛盾机理及合理井距分析[J].石油勘探与开发,2003,30(1):87-89.
• [10]时佃海.低渗透砂岩油藏平面径向渗流流态分布[J].石油勘探与开发,2006,33(4):491-494.
• [11]蒋利平,李茂,姜平,等.低流度油藏考虑启动压力和压敏效应的渗流特征[J].大庆石油地质与开发,2011,30(6):88-93.
• [12]孙黎娟,吴凡,赵卫华,等.油藏启动压力的规律研究与应用[J].断块油气田,1998,5(5):30-33.
• [13]何贤科,陈程.低渗透油田建立有效驱替压力系统研究[J].特种油气藏,2006,13(2),56-57.
• [14]程杰成,朱维耀,姜洪福.特低渗透油藏CO2驱油多相渗流理论模型研究及应用[J].石油学报,2008,29(2):246-251.
• [15]李松泉,程林松,李秀生,等.特低渗透油藏非线性渗流模型[J].石油勘探与开发,2008,35(5):606-612.
• [16]苏玉亮,吴春新,张琪,等.特低渗透油藏CO2非混相驱油特征[J].重庆大学学报,2011,34(4):53-57.
• [17]汪全林,柴世超,程自力,等.基于两相流低渗油藏合理注采井距确定方法[J].东北石油大学学报,2012,36(4):45-48.
• [18]吕爱民,姚军.裂缝性碳酸盐岩底水油藏合理打开程度与合理井距[J].石油勘探与开发,2008,35(1):97-100.
• [19]凌宗发,王丽娟,胡永乐,等.水平井注采井网合理井距及注入量优化[J].石油勘探与开发,2008,35(1):85-91.
• [20]李松泉,程林松,李秀生,等.特低渗透油藏合理井距确定新方法[J].西南石油大学学报(自然科学版),2008,30(5):93-96.
• [21]张建国,雷光伦,张艳玉.油气层渗流力学[M].东营:石油大学出版社,1998:148-150.
• [22]程林松.渗流力学[M].北京:石油工业出版社,2011:178-190.
• [23]Chung T H,Jones R A.Measurements and correlations of the physical properties of CO2/heavy-crude-oil mixtures[R].SPE15080,1988:822-828.