摘要
多种研究表明,在裂缝性地层中,水力裂缝由于受天然裂缝作用的影响可能延伸为多分支、非平面的复杂裂缝体系。从矿场试验、室内实验、数字实验和图貌监测4个方面分别论证裂缝性油气藏压裂过程中天然裂缝的存在对水力裂缝延伸的影响,并分析裂缝性地层水力裂缝沿天然裂缝的非平面延伸规律。矿场相交试验结果表明,在地质非连续体地层中,压裂后的水力裂缝多以分支缝的方式延伸;室内相交实验发现,在一定的逼近角和水平主应力差条件下,天然裂缝会改变水力裂缝的延伸形态和扩展模式;数值模拟方法和微地震监测证实,裂缝性储层水力压裂后所形成的裂缝体系是复杂的缝网系统。裂缝性地层中水力裂缝呈复杂的非平面延伸,与均质地层压裂产生的对称双翼平面裂缝有很大差异。
A variety of researching methods show that in naturally fractured formations, the hydraulically created fractures may propagate into multi-branched, non-planar complex fracture system due to the influences of the natu- ral fractures. From the viewpoints of the following four aspects： field tests, laboratory experiments, digital experi- ments and figure monitoring, the influences of the natural fractures on the propagation of the hydraulic fractures are seperatively demonstrate in the process of fracturing the naturally fractured petroleum reservoirs. In the meantime, the non-planar propagation rules of the induced fractures along the natural ones in the fractured formations are ana- lyzed. The results of the intersecting field tests show that the induced hydraulic fractures stretch in a multi-branched way in the geologically discontinuous formations, the indoor intersecting experiments find that the natural fractures can change the propagation morphology and expansion patterns of the hydraulic ones under a certain conditions of approaching angle and horizontal principal differential stress. Numerical simulation method and microseismic moni-toring confirm that the fracture system is a complex fracture network one after the hydraulic fracturing of the natural- ly fractured formations. The hydraulic fractures in the naturally fractured formations possess complex non-planar propagation, there are a serious differences from the bi-wing symmetric and planar fractures generated in the fractu- ring of the homogeneous formations.
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2013年第5期92-97,共6页
Petroleum Geology & Oilfield Development in Daqing
基金
国家科技重大专项"大型油气田及煤层气开发"(2011ZX05014)
关键词
裂缝性地层
水力裂缝
裂缝形态
天然裂缝
非平面延伸
fractured formation
hydraulic fracture
fracture morphology
natural fracture
non-planar propaga-tion
作者简介
叶静，女，1987年生，在读硕士，从事油气田增产理论与技术研究。E—mail：y@ng5207．m@163．com
