非均质中低渗透油藏凝胶调驱井区筛选方法研究与应用

This project is aimed at the problem of poor efficacy by water flooding at the late stage of high water cut development in D Oilfield heterogeneous medium and middle-low permeability reservoirs, to circumvent investment risks and get better economic benefits, it is necessary to carry out the research of screening method for profile control and displacement blocks, so that to put forward a set of targeted and integrated screening method for profile control and displacement blocks and implement the application. Firstly, this project based on precise description technique and displacement pilot test dynamic analysis technique, through the analysis of reservoir geological factors and development dynamic factors on the effect of displacement, to determine the potential evaluation parameters for profile control and displacement blocks of the D oilfield; Then, using the combination of indoor physical simulation experiments and mathematical statistics to determine the evaluation rating boundary of potential evaluation parameters; Then, using the comprehensive evaluation method based on variable fuzzy set theory to classify and optimize potential wells, and screen potential blocks; At last, through the indoor physical simulation experiments, numerical simulation studies and field test results tracking evaluation in potential blocks, to apply and verify the practicality and reliability of the screening method for profile control and displacement blocks in heterogeneous medium and middle-low permeability reservoirs. This project study can provide a theoretical basis and technical solution for the effective development of D oilfields, and can provide a set of referable potential blocks screening methods that can be used for other middle-low permeability reservoirs.

本项目针对D油田非均质中低渗透油藏高含水开发后期水驱受效差的问题，为了规避投资风险、获得更好的经济效益，有必要开展调驱井区筛选方法研究，以便能提出一套有针对性的、完整的深部调驱井区筛选方法并实施应用。本项目首先基于油藏精细描述技术和调驱先导性试验动态分析技术，通过分析油藏地质因素和开发动态因素对调驱效果的影响，确定D油田调驱井区潜力评价参数；其次，利用室内物理模拟实验和数理统计相结合方法确定潜力评价参数的评价分级界限；然后，利用基于可变模糊集的综合评价方法对潜力井进行分类和优选，从而筛选出调驱潜力井区；最后，通过开展潜力井区室内物理模拟实验、数值模拟研究以及现场试验效果跟踪评价，应用并验证本项目所研究的非均质中低渗透油藏调驱井区筛选方法的实用性和可靠性。该项目研究可为D油田的有效开发提供理论基础和技术方案，同时可为其它中低渗透油藏实施调驱提供一套可以借鉴的潜力井区筛选方法。

目前国内中低渗透油藏在我国已探明的石油储量中越来越大，潜力巨大。但该类油藏纵向上、平面上非均质性强，造成注入水低效、无效循环严重，单靠水驱所能增加的产量少之又少，经济效益逐年变差，故迫切需要一种适用于中低渗透油藏的提高采收率技术。本次研究针对D油田非均质中低渗透油藏高含水开发后期水驱受效差的问题，基于油藏精细描述技术和调驱先导性生产动态分析技术，结合油藏地质、开发、措施等数据，对不同油藏地质因素和开发动态因素对调驱效果的影响规律进行了深入的分析，确定了D油田调驱井区潜力评价参数共7个，并利用室内物理模拟实验在多种连续相及非连续相调驱体系中筛选出适用于中低渗透油藏的调驱体系为复合离子型凝胶调驱体系；针对已优选出的调驱潜力井区潜力评价参数，利用室内物理模拟实验和数理统计相结合方法确定潜力评价参数的评价分级界限；基于潜力评价参数分级评价界限的基础上，利用基于可变模糊集的综合评价方法对调驱潜力井进行分级和优选，筛选出D油田中PB-2井区为适用于调驱技术开发的潜力井区；最终以调驱潜力井区油藏参数作为依据，完成了调驱注入参数优选实验，优选出最优聚合物浓度为900mg/L，交联剂浓度为1400mg/L，注入量为0.18PV，注入速度为0.06PV/a，预测后续水驱含水率达到98%时可在水驱基础上提高采收率7.31%，财务净现值达到5830.6万元，投资回收期4.3年，并对注调驱体系阶段矿场试验效果进行跟踪评价，从而验证本项目所研究得出的非均质中低渗透油藏调驱井区筛选方法的实用性和可靠性。该项目所得出的研究成果为D油田高含水后期高效开发提供了理论基础和技术方案，同时为其它中低渗透油藏实施调驱提供一套可以借鉴的潜力井区筛选方法。在研期间，共发表论文12篇，其中SCI、EI检索3篇，共申请发明专利3项，其中授权1项，参加国内、国际学术交流会议10人次，共培养博士生3名、硕士生12名。