作 者: ;
机构地区: 西北大学地质学系地质系
出 处: 《西北地质科学》 1997年第1期50-54,共5页
摘 要: 在鄯善油田宏观裂缝研究的基础上,对储层微裂缝进行了研究,获得以下主要认识:1.鄯善油田发育的微裂缝按照成因分类有成岩微裂缝、颗粒微裂缝和定向微裂缝。前两种裂缝为成岩作用或破碎作用形成,后者在构造作用下形成。按照形态分类有完全充填的、不完全充填的、开启的和闭合的微裂缝。不同形态的微裂缝对注水开发的影响不同。2.该区微裂缝主要集中在0.005~0.02mm范围内,占全部微裂缝的70%以上。3.微裂缝以充填为主,镜下观察80%以上的微裂缝被碳酸钙所充填,从而大大降低了微裂缝的有效性。微观水驱油模型试验也显示,仅20%左右的微裂缝可成为油水通道。4.微裂缝的延伸有3种情况:a.微裂缝中止于颗粒内部;b.微裂缝延伸之颗粒边缘;c.微裂缝延伸长,可切穿几个颗粒,且可与其他微裂缝形成网络。微裂缝的延伸方向主要有NE66°、NE137°,其延伸方向不与大裂缝一致,夹角约为40°。5.微裂缝在大裂缝附近较发育,受大裂缝控制。 Based on the study of macro-fracture in shanshan oilfield, we study micro-fractures andobtain the following knowledge: 1. Micro-fractures can be divided Into three types the diagenesis, particle and orientation micro-fracture according to the course of formation. Theyform in the course of diagenesis, crushing and tectonism, respectively. Micro-fractures canalso be divided into completely-filled, partly-filled, closed, and open micro-fracture on thebasis of morphology. And, different kinds of micro-fractures have different effects on thewaterflood develop. 2. Micro--fractures, whose width ranges mainly from 0. 005 to 0. 02 mm,account for 70 percent. 3. The fact that over 80 percent of micro--fractures are filled with calcium carbonate reduced their validity. Moreover, the micro water--drive test shows that only20 percent of micro-fractures can be passed through by fluid. 4. there are three kinds of extension of micro-fractures: 1) micro-fractures end in particles. 2) micro--fractures reach tothe edge of particles. 3) micro-fractures extend long enough to cut several particles and formthe network with other microMfractures. And micro-fractures, which are not parallel to rnacio-liactures at angles of about 40' between them, extend mainly along the direction of NE66'and NE137'. 5. Micro--fractures develop close to macro-fractures and are as well controlled bythem.
领 域: [石油与天然气工程] [石油与天然气工程]