基于Lattice Boltzmann方法的页岩张性裂缝渗流特征研究  

Seepage Characteristics of Tension Fractures in Shale Based on Lattice Boltzmann Method

作　　者：曲冠政 周德胜[1] 彭娇[1] Randy Doyle Hazlett Siwei Wu 

机构地区：[1]西安石油大学,陕西西安710065 [2]The University of Tulsa McDougall School of Petroleum Engineering,Tulsa,74104,USA

出　　处：《特种油气藏》2018年第1期134-139,共6页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金“低温压裂液注入促进缝网形成的力学机理研究”(51604225);国家科技重大专项“大型油气田及煤层气开发”之“鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程--低渗透致密砂岩气藏压裂裂缝及参数优化”(2016ZX05050-009)

摘　　要：为深入了解张性裂缝结构中流体渗流特征,采用物理实验和数值模拟相结合的方法,系统研究流体在页岩张性裂缝中的渗流特征。将Barnett页岩岩心劈裂成张性裂缝,并采集裂缝面数据,将其作为物理模型,同时采用LBM-BKG方法 D3Q19模型研究流体在张性裂缝中的流动。研究尺度依次为整体、截面、截线、离散单元体,考察各尺度下渗流场特征参数分布,并分析原因。研究表明:整体上,沿渗流横向和纵向上压力均呈线性分布,横向各截线上压力呈波动式线性分布,纵向截线上压力分布呈非线性;缝面端部局部区域会产生回流区,回流区与粗糙性及粗糙性变化程度有关;近平均速度的速度等值面间基本呈平行分布,速度较大时,等值面基本对应于端面相对平缓的区域;沿同一流线,渗流速度略有差别;整体渗流为稳态,不代表渗流场各处速度相等,离散的渗流单元体的渗流速度各不相同;三维粗糙性造成了渗流速度的三维分布,但主要以渗流方向和垂向上渗流速度为主。该项研究对深入理解页岩等裂缝发育储层的裂缝系统渗流具有重要意义。In order to deeply understand the fluid seepage charaeteristics in tension fractures slructure, the seepage eharacteristies of fluid in shale tension fracts are systematieafly studied by enmbining physical experiment and numerieal simulation. Split up the Barnett shale core into tensional fractures, collect the fracture surIhcc data as a physical model, and at the same thne, study fluid flow in tension fraetures by using the D3019 model of LP, M- BKG method. Researeh seale are whole, section,line, discrete element in turn. Investigate the distribuliun of seep- age field characteristic paramemrs under various scales and analyze the reasons. Reseamh shows that： on the whole, pressure is linear distribution ahmg the lateral and vertical of seepage, and it is fluetuant linear distribution nu lateral lines, while nonlinear distributinn on vertical lines; a recirculation zone is formed in the local region at the end of the joint surface, which is related to the roughness and the degree of roughness; velocity isosurface uear average velocity are basically parallel, when the velocity is large, the velocity isosurfaee hasieafly corresponds to the region with relatively smooth emt surface; along the same streamline, there is a slight difference in seepage velncity; the whole seepage is steady, and it does not mean the velocity is equal everywhere in the seepage fMd, actually the seepage velocity of discrete seepage elements are different; the 3D roughness caused three dimensiomd distribution of seepage velocity, hut mainly based on the flow direction and vertical seepage velocity. This study is of great sig- nificance tier understamting the seepage of fractured system in fiactured reservuirs such as shale.

关 键 词：LATTICE Bohztnann方法 张性裂缝 页岩渗流特征 数值模拟 

分 类 号：TE319[石油与天然气工程—油气田开发工程]