摘要
页岩气产能提高的主要方式是长水平井多段多簇水力压裂制造大规模的沟通缝网。为了进一步提升开发储层动用率,尤其是储层纵向动用程度,探索了储层开发的体积开发模式。相对于单井开采,体积开发需要考虑层间气体动用的问题。根据层间干扰强度划分层间沟通模式为:层间不沟通、层间渗流沟通和层间缝网沟通。结合势的叠加原理和流场边界层效应建立层间渗流沟通判据和计算模型。通过引入裂缝应力敏感的页岩气基质-裂缝渗流修正方程和主裂缝-次生裂缝-基质三重介质模型描述页岩气多尺度输运,揭示和评价了3种沟通模式下的长宁区块龙马溪组页岩气开采效果。结果表明:层间渗流沟通的体积开发模式最终产能提升效果显著,相较于单井开发叠加,估算的最终可采储量(estimated ultimate recovery,EUR)可增加0.25×10^8 m^3,增加比例达9.84%。缝网沟通过强的储层改造程度使储层流体压力下降过快,应力敏感现象显著,中后期开采能力下降严重,最终影响到整个产层储量的有效动用。体积开发三种模式中渗流沟通效果最好,缝网沟通和层间不沟通采收效果相当。该研究为实现储层体积开发高效动用所需的合理立体井位布置和压裂施工方案提供了理论指导。
The main way to increase the capacity of shale gas is to generate large-scale communication fracture by multi-segment and multi-cluster hydraulic fracturing on long horizontal wells.To enhance the utilization degree of developed reservoirs,especially the vertical utilization of reservoirs,the volume development model of reservoir development was explored.Compared with single well development,the volume development needs to consider the problem of interlayer gas utilization.According to Inter-layer interference intensity,the communication mode between layers could be divided into no communication,flow communication,and turbulent flow communication.The communication criterion and calculation model of interlayer seepage combined was established in potential superposition principle and the effect of flow field.By introducing the gas-shale matrix-fracture seepage correction equation and the main fracture-secondary fracture-substrate triple media model,the multi-scale transport of shale gas was described and the production effect of gas-shale play in Longmaxi Formation in Changning Block,was appraised and demonstrated under the conditions of three connection models.The results show that the three-dimensional development model of interlayer seepage communication has a significant effect on final productivity improvement.Compared with single well development,the estimated ultimate recovery is increased by 0.25×10^8 m^3,or an increase of 9.84%.The seam network drops the reservoir fluid pressure very fast due to the strong reservoir reformation,the stress sensitivity is significant,the mining capacity in the middle and late stages is heavily reduced,and the effective use of the entire production reserve is affected.Among the three modes of volume development,the seepage communication effect is shown the best,and the seam network communication is equivalent to the non-interlayer communication.This study provides theoretical guidance for rational three-dimensional well placement and fracturing construction schemes required for the efficient development of reservoir three-dimensional development.
作者
张彦从
刘先贵
胡志明
端祥刚
李亚龙
ZHANG Yan-cong;LIU Xian-gui;HU Zhi-ming;DUAN Xiang-gang;LI Ya-long(University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Porous Flow and Fluid Mechanics,Chinese Academy of Science,Langfang 065007,China;Research Institute of Petroleum Exploration and Development,Langfang 065007,China)
出处
《科学技术与工程》
北大核心
2020年第27期11092-11098,共7页
Science Technology and Engineering
基金
国家科技重大专项(2017ZX05037-001)。
关键词
页岩气
体积开发
层间渗流
沟通判据
产能评价
shale gas
multi-layer mining
interlayer seepage
communication criterion
capacity evaluation
