摘要
随着海上新发现的常规油气资源量越来越少,低渗油气储量的动用问题是决定海上油气增储上产的关键,低渗油气储量的动用依赖于适合岩性构造的水力压裂工艺。为了搞清海上低渗油藏的压裂可行性,针对3H水平井所在层位的构造特征、物性特征和岩性特征复杂的特点,开展了岩石力学参数、综合脆性指数及三维地应力参数计算,并评价了3H水平井段体积压裂可行性。结果表明:1)沙四段至中生界杨氏模量为31.80~35.66 GPa,泊松比为0.20~0.23,地层抗压强度为26.8~30.3 MPa,内摩擦角为42.7°~44.8°;2)3H水平井综合脆性指数高于40%,水平主应力差为3.30~3.65 MPa,整体偏小,具备形成复杂缝网的地质和工程方面的条件。以上成果认识,对海上砂岩储层低渗储量的有效动用具有重要的意义。
Producing oil and gas reserves in low-permeability reservoirs is the key to increasing offshore oil and gas reserves,and production for conventional oil and gas resources discovered in the sea is becoming less and less.Producing oil and gas reserves in low-permeability reservoirs depends on hydraulic fracturing technology suitable for lithology and structure.To understand the fracturing feasibility in offshore low-permeability reservoirs,rock mechanics parameters,comprehensive brittleness index,and three-dimensional in-situ stress parameters were calculated according to the complex structural,physical,and lithological characteristics of the horizontal well 3H formation,and the volumetric fracturing feasibility was evaluated in the horizontal section of well 3H.The results show that:1)The Young’s modules,the Poisson’s ratios,the compressive strength,and the internal friction angles of formation from the 4 th Member of Eocene Shahejie Formation(Es 4)and the Mesozoic are between 31.8 GPa and 35.66 GPa,0.20 and 0.23,26.8 MPa and 30.3 MPa,42.7°and 44.8°,respectively.2)The comprehensive brittleness index of the horizontal well 3H is higher than 40%,and the horizontal principal stress differences are smaller than 3.3 MPa~3.65 MPa,which has geological and engineering conditions for forming complex fracture networks.These results are significant to the effective producing reserves in offshore low-permeability sandstone reservoirs.
作者
江锚
张丽平
周俊
彭成勇
邹剑
JIANG Mao;ZHANG Liping;ZHOU Jun;PENG Chengyong;ZOU Jian(CNOOC Research Institute Co.,Ltd.,Beijing 100028,China;Tianjin Branch of CNOOC(China)Limited,Tianjin 300459,China)
出处
《非常规油气》
2024年第3期130-138,共9页
Unconventional Oil & Gas
基金
中海油集团有限公司重大科技项目“海上低渗透油藏压裂开发地质工程一体化研究技术研究”(KJGG2022-0701)。
关键词
沙河街组
天然裂缝
脆性指数
体积压裂
水平应力差
Shahejie Formation
natural fracture
brittleness index
volume fracturing
horizontal stress difference
