十屋油田营城组储层裂缝特征及有效性分析

Characteristics and Effectiveness Analysis on the Fractures in Yingchen Formation of Shiwu Oilfield

通过对研究区现有岩心的观察描述,利用钻井、试油等资料,详细探讨了十屋油田营城组储层裂缝特征,并从构造运动和现今地应力2个方面对裂缝的有效性进行了分析。结果表明,研究区裂缝以高角度斜交缝和直劈缝为主,力学性质表现为剪性缝和扭张缝;裂缝充填程度主要为半充填,主要充填方解石和泥质;虽然存在多组裂缝方向,但以北东向、近南北向裂缝占优势,其次为北西和北北东向裂缝;主要在营城组末期和登娄库组末期北西向构造应力作用下形成裂缝。在现今地应力作用下,东西向裂缝有效程度高,成为影响十屋地区开发布井的重要裂缝组系。

Through observation of the existing core,by using drilling and oil test data,the fracture characteristics are discussed in detail,fracture effectiveness is analyzed from the present-day tectonic movement and stress cracks.The main Fractures are high-angle oblique fractures and vertical fracture,the mechanical properties are shear and twisted fractures.The degree of fracture is semi-filling and filling with calcite and clay.Although there are multiple fracture directions,but the north-east,north-south fracture are dominant,followed by the north-west and NNE fractures.Fractures are formed during the end of Yingcheng and Denglouku Formations under the NW tectonic stress.In the present-day stress,EW fracture has a high effectiveness of fracture,it is an important fracture group,which affects the development and well spacing in Shiwu Area.