致密油藏水平井多级压裂储层改造体积评价

Evaluation of Stimulated Reservoir Volume(SRV) in Tight Oil Reservoirs by Horizontal Well Multistage Fracturing Process

基于昌吉油田中二叠统芦草沟组致密油藏建立水平井多级压裂仿真模型,研究天然裂缝、裂缝参数、裂缝形态等因素对储层改造体积和油井累计产量的影响,结果表明:在开发早期,裂缝参数是影响油井累计产量的主要因素;进入开发中后期,储层改造体积对油井累计产量的控制作用开始凸显。次级裂缝和裂缝条数是影响储层改造体积和油井累计产量的主要因素,且次级裂缝、裂缝渗透率和裂缝半长对油井累计产量的影响主要集中在开发早期,裂缝间距和裂缝形态的影响主要在开发中后期,而裂缝条数的影响则贯穿整个生产开发过程;梭形、喇叭口形和均匀形裂缝形态对应的储层改造体积基本相同,而哑铃形裂缝对应的储层改造体积较小。

Based on the Middle Permian Lucaogou tight oil reservoir characteristics in Changji oilfield, this paper developed the simulation model of horizontal well multistage fracturing process, and by which studied the effects of nature fractures, fracture parameters and fracture shapes on the stimulated reservoir volume （SRV） and cumulative oil production. The results show that during early stage of exploitation, frac- ture parameters are the main factors affecting the production of oil wells; after entering into middle-late stage, SRV has more and more control effect on the production; while the secondary fractures and the number of fractures are the main factors affecting SRV and cumulative oil pro- duction. And the effects of secondary fractures, fracture permeability, and half-length of fracture on the well cumulative production are fo- cused on the early period of development; the effects of the spacing and geometry of fractures are focused on the middle-late stage of develop- ment. The influence of the number of fractures runs through the entire development period. The SRV values corresponding to shuttle, trumpet and uniform types of fractures are approximately the same, while the SRV value for dumbbell type of fracture is smaller.