考虑渗吸效应的致密油藏体积改造可行性分析

发布时间：2018-01-23 02:55

本文关键词： 致密油藏体积改造渗吸效应毛管力重力　出处：《地质科技情报》2017年06期 　论文类型：期刊论文

【摘要】：为探究致密储集层在毛管力、重力作用下的渗吸机理,考虑致密储集层特征(相渗、毛管力等),推导出了一维两相逆向渗吸模型,利用Mattax和Kyte方法对时间无因次处理后,采用差分方法进行求解,给出了3种边界条件下方程的解,并对常规砂岩和致密岩心渗吸结果进行了对比。结果表明:(1)体积改造后形成复杂缝网,储集层渗吸作用可分为重力辅助渗吸、重力抑制渗吸和零重力渗吸;(2)尽管致密储集层孔喉半径小,毛管压力高,渗吸动力强,但由于其孔渗条件差,流体流动受限,综合来说其饱和度前缘慢于常规高渗储集层;(3)毛管力在常规砂岩和致密储集层的渗吸中均起主导作用,重力在高渗砂岩渗吸中表现明显,而在致密储集层渗吸中表现不明显;(4)对于致密储集层,通过水平井分段多簇、细分切割,甚至"体积改造"的压裂模式,增加润湿相与裂缝壁面的接触面积和接触体积,则可充分发挥渗吸作用,置换出更多的油气,提高原油产量。新疆油田玛18区块现场试验表明,致密储集层发挥渗吸作用可提高原油产量2~4t/d。
[Abstract]:In order to explore the permeability mechanism of dense reservoir under the action of capillary force and gravity, a one-dimensional two-phase reverse permeation model was derived, considering the characteristics of dense reservoir (phase permeability, capillary force, etc.). After processing time dimensionless by Mattax and Kyte method, the difference method is used to solve the equations. The solutions of the equations under three boundary conditions are given. The results of conventional sandstone and tight core infiltration are compared. The results show that the complex fracture net is formed after volume reformation, and the permeability and suction of reservoir can be divided into gravity assisted infiltration and suction. Gravity inhibits osmotic absorption and zero gravity osmosis; (2) although the pore throat radius of tight reservoir is small, the capillary pressure is high, and the permeability is strong, the fluid flow is limited because of its poor pore and permeability conditions, and the saturation front edge is slower than that of the conventional high permeability reservoir. (3) the capillary force plays a leading role in both conventional sandstone and tight reservoir, gravity is obvious in high permeability sandstone, but it is not obvious in tight reservoir. 4) for tight reservoir, the contact area and contact volume between wetting phase and fracture wall can be increased through the fracturing mode of horizontal wells with multi-clusters, subdivision and cutting, and even "volume modification". The field test in Ma18 block of Xinjiang Oilfield shows that the tight reservoir can increase the oil production by 2 t / d.
【作者单位】：中国石油勘探开发研究院;中国石油勘探开发研究院廊坊分院;中国石油大学(北京)石油工程教育部重点实验室;
【基金】：国家科技重大专项“大型油气田及煤层气开发”(2016ZX05023)
【分类号】：P618.13;TE357
【正文快照】： 3.中国石油大学(北京)石油工程教育部重点实验室,北京102249)渗吸是指在毛管力和重力作用下,多孔介质自发地吸入某种润湿性流体而排出非润湿性流体的过程[1]。渗吸有2种形式:同向渗吸和逆向渗吸。当润湿相的吸入方向与非润湿相的流出方向相同时,称之为同向渗吸;反之,称之为逆

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