摘要
致密砂砾岩油藏水平井分段射孔压裂过程中,地层破裂压力高、压开难度大,借助酸液预处理工艺降低泵压又出现泡酸耗时长的问题,显著降低了压裂时效。通过明确不同酸处理参数条件下的矿物溶蚀规律有助于酸处理方案优选,从而有效降低地层破裂压力。基于半变差函数模型和向量差积法,建立了考虑玛湖非均质储层矿物组分特征的酸化模型,量化分析酸液预处理过程中的矿物溶蚀程度及规律。研究表明,玛湖油藏长石含量较高,碳酸盐岩含量较低,土酸具有更好的溶蚀效果,以及通过土酸在现场的成功应用充分证明了其降低玛湖储层破裂压力的可行性;随着酸浓度的降低,酸蚀作用减弱,不利于降低破裂压力;酸岩作用时间存在拐点,单纯地增加泡酸时间并不能提升酸处理效果。建议现场通过合理优选酸液体系、适当增加用酸浓度等方法,提高酸液预处理效率。文章研究成果对玛湖现场酸液预处理方案制定具有一定的指导意义。
In the process of horizontal well segmented fracturing in tight glutenite reservoirs,the formation breakdown pressure is high and the fracturing development is difficult.The acid pretratment is applied to reduce the pump pressure,which is time-consuming with low fracturing success rate.Clarification of the mineral dissolution laws under different acidizing parameters is helpful for the optimization of acid pretreatment schemes and formation breakdown pressure reduction.Based on a semi-variogram function model and vector cross product method,the acidizing model considering the mineral composition characteristics of the heterogeneous reservoir in Mahu was established to quantitatively analyze the mineral dissolution law during acid pretreatment process.The study shows that the Mahu reservoir has relatively high content of feldspar and low content of carbonates.The mud acid has a better dissolution effect,and the successful application in the field has fully demonstrated the feasibility.The acid concentration rapidly decreases,the acid action weakens,which is not conducive to lower the breakdown pressure.There is a turning point in the acidizing time,and simply increasing it cannot improve the acid pretreatment effect.The acid pretreatment performance can be improved by appropriately optimizing acid type and increasing acid concentration.The numerical model established in this research provides a theoretical basis for the design of acid pretreatment schemes in the Mahu tight reservoir.
作者
贾文婷
牟建业
王贵富
张士诚
马新仿
王雷
JIA Wenting;MOU Jianye;WANG Guifu;ZHANG Shicheng;MA Xinfang;WANG Lei(National Key Laboratory of Petroleum Resources and Engineering,Beijing 102249,China;China University of Petroleum(Beijing),Beijing 102249,China;CNPC Engineering Technology R&D Company Limited,Beijing 102206,China)
出处
《钻采工艺》
CAS
北大核心
2024年第3期108-114,共7页
Drilling & Production Technology
关键词
致密砂砾岩油藏
酸液预处理
射孔完井
数值模拟
工程设计
tight glutenite reservoirs
acid pretreatment
perforation completion
numerical simulation
construction design
作者简介
贾文婷(1992-),女,在读博士,从事致密储层压裂改造相关研究。地址:(102249)北京市昌平区府学路18号中国石油大学,E-mail:17709906237@163.com。
