川中地区大安寨段页岩油储层可压性评价实验  

Experimental Evaluation on Compressibility of Shale Oil Reservoir in Da′anzhai Section in Central Sichuan Area

作　　者：王良 杨建[1,2] 彭钧亮 陈岗 韩慧芬[1,2] 张曦 WANG Liang;YANG Jian;PENG Junliang;CHEN Gang;HAN Huifen;ZHANG Xi(Engineering Technology Research Institute of Southwest Oil&Gas field Company,PetroChina,Guanghan,618300,China;Shale Gas Evaluation and Exploitation Key Laboratory,Chengdu,Sichuan 610051,China;Chuan Zhong Oil and Gas De-posits of Southwest Oil&Gas field Company,PetroChina,Guanghan,Sichuan 629000,China)

机构地区：[1]中国石油西南油气田分公司工程技术研究院,四川省广汉市618300 [2]页岩气评价与开采四川省重点实验室 [3]中国石油西南油气田分公司川中油气矿

出　　处：《钻采工艺》2023年第1期163-168,共6页Drilling & Production Technology

基　　金：中国石油西南油气田分公司2021年科研项目“川中大安寨段页岩油储层与压裂液相互作用机理研究”(编号:20210302-06)部分研究内容。

摘　　要：川中大安寨段页岩油储层主要发育在大二亚段,资源基础丰富,勘探开发潜力大,但工程地质特征及可压性评价手段不明确。为建立可压性评价方法、优化储层改造对策及工艺技术,开展了一系列储层工程地质特征实验,结果表明:川中大安寨以页岩和灰岩互层为主,有机碳含量相对较低,脆性矿物含量大于50%,孔隙度平均为5.9%,孔隙主要集中在0.001~0.1μm范围,发育有微米级孔隙;矿物组分以石英、白云石和方解石为主,平均黏土矿物含量41%,平均岩石力学脆性指数为58.5%;储层天然裂缝发育程度不高,灰岩段破裂压力与页岩段差值9~10 MPa,不利于裂缝在纵向上扩展。文章建立了页岩油储层可压性模型,基于页岩油储层可压性及岩性特征,提出了通过提高缝内净压力以实现层间突破、采取密切割压裂+暂堵转向的组合储层改造工艺来提高裂缝复杂程度的技术对策。通过现场试验,川中地区大安寨段页岩油储层改造效果从最初的油花微气到日产油2 m^(3)/d,现场应用效果不断突破。The shale oil reservoir of Da′anzhai section in central Sichuan,mainly developed in da-er sub-section,has rich resources and great potential for exploration and development.A series of experiments on reservoir engineering geological characteristics have been carried out in order to form the countermeasures and techniques for reservoir reconstruction suitable for Da′anzhai shale oil.The result shows:the Da′anzhai area in central Sichuan is mainly interbedded with shale and limestonethe,the content of organic carbon is relatively low,the content of brittle mineral is more than 50%,the average porosity is 5.9%,the pore mainly concentrates in the range of 1~100 nm,the main peak is 25 nm,the slightly bigger pore mainly concentrates in the range of 250~1 000 nm,and develops the micron scale pore.The main mineral components are quartz,dolomite and calcite.The average content of clay minerals is 41%.The reservoir has characteristic of certain plastic.The average rock mechanical brittleness index is 58.5%.The natural fractures of reservoir are not well developed,the difference of fracture pressure between limestone section and shale section is 9~10 MPa,which is unfavorable to fracture propagation in longitudinal direction.Based on the compressibility and lithologic characteristics of the shale oil reservoir,a compressibility model for the Da′anzhai shale oil reservoir in Sichuan Basin was established.The technical approach to improve the complexity of fractures is to increase the net pressure in fractures to achieve interlayer breakthrough,and to adopt the combination of close cutting fracturing and temporary plugging to change direction.From initial minor amount to 2 cubic meters per day,successful stimulation results have been obtained after the transformation of Da′anzhai shale oil reservoir in central Sichuan area.

关 键 词：川中地区 大安寨段 页岩油 工程地质特征 可压性 

分 类 号：TE357[石油与天然气工程—油气田开发工程]