河道致密砂岩螺旋射孔完井压裂优化设计  

Fracturing Optimization Design of Spiral Perforation Completion in Tight Sandstone Channel

作　　者：范宇 汤继周 陈伟华 张卓 唐波涛 杨文涛 FAN Yu;TANG Jizhou;CHEN Weihua;ZHANG Zhuo;TANG Botao;YANG Wentao(Engineering Technology Research Institute of Southwest Oil&Gas Field Company,PetroChina,Chengdu,Sichuan 610017,China;School of Ocean and Earth Science,Tongji University,Shanghai 200092,China;State Key Laboratory of Marine Geology,Tongji University,Shanghai 201306,China;College of Chemistry,Nankai University,Tianjin 300071,China)

机构地区：[1]中国石油西南油气田公司工程技术研究院,四川成都610017 [2]同济大学海洋与地球科学学院,上海200092 [3]同济大学海洋地质国家重点实验室,上海201306 [4]南开大学化学学院,天津300071

出　　处：《测井技术》2021年第6期646-656,共11页Well Logging Technology

基　　金：中国石油西南油气田分公司工程技术研究院科研项目“川中地区沙溪庙组致密气关键工程技术研究”(2021Y-01)。

摘　　要：川中地区秋林区块沙溪庙组河道致密砂岩储层存在低孔隙度特低渗透率、储层非均质性强、脆性指数低等特征,前期采用水平井分段多簇螺旋射孔改造后,发现射孔效率低、储层改造效果不明显。基于三维离散格子法建立油田尺度水力压裂等效螺旋射孔模型,分别对致密砂岩储层弹性模量、射孔孔径、相位角以及压裂簇间距开展敏感性参数分析,以便对压裂参数进行优化设计。研究结果表明:川中地区秋林区块沙溪庙组河道致密砂岩储层弹性模量是影响射孔效率及储层改造均匀性的主控因素,在较小模量区域施工所需的破裂压力低,应力阴影作用较小,储层改造体积较均匀;使用较大射孔孔径会明显增大簇间干扰,但整体裂缝改造更均匀,也有利于后续加砂;布孔时采用与地应力方向相同的射孔能有效降低应力阴影影响,而增大射孔相位角会减少流线弯曲进而降低裂缝起裂的难度;较小压裂簇间距会增大裂缝起裂的破裂压力,簇间干扰会更明显,裂缝横向扩展差异性更大。The tight sandstone reservoirs in the Shaximiao formation in the Qiulin block of central Sichuan basin have the characteristics of low porosity and ultra-low permeability,strong reservoir heterogeneity,and low brittleness index.The early development through multi-cluster horizontal fracturing with spiral perforation completion manifests low perforation efficiency and unapparent stimulation.Based on the three-dimensional lattice method,the field-scale hydraulic fracturing with equivalent spiral perforation cluster model is established in this paper.The sensitivity analyses for the key parameters of the tight sandstone reservoir including elastic modulus,perforation diameter,perforation phase angle,and cluster spacing are carried out to implement fracturing optimization design.The following results are obtained.The elastic modulus of the channel sandstone reservoir in the Shaximiao formation tight sandstone reservoirs of the Qiulin block in central Sichuan basin is the main controlling factor for perforation initiation and the uniformity of reservoir stimulation.The breakdown pressure required for crack initiation in the smaller elastic modulus area is lower,and the stress shadow effect becomes less obvious.Moreover,the stimulated reservoir volume will be more uniform.Applying alarger perforation diameter will significantly increase the interference between clusters,but the overall fracture geometryis more uniform.Besides,using a larger perforation diameter is also conducive to subsequent slurry injection.Arranging perforation channels in the same direction as the in-situ stress can effectively mitigate the stress shadow effect.In addition,increasing the phase angle will reduce streamline bending and make perforation initiation easier.The smaller the cluster spacing,the larger the breakdown pressure for perforation initiation.Moreover,the clusters’interference will be more obvious,and the lateral propagation of cracks will become less uniform.

关 键 词：致密砂岩 离散元 水力压裂 螺旋射孔 簇间干扰 川中地区秋林区块沙溪庙组 

分 类 号：P631.84[天文地球—地质矿产勘探]