页岩气水平井试井模型及井间干扰特征

页岩气田采用水平井井网大规模开发后，井间干扰造成的“压力下降快、气井过早废弃”的问题日益严重，亟须认识页岩气井的井间干扰特征。为此，先将水平井多段压裂改造后的页岩储层划分为压裂裂缝、SRV和未改造基质3个区域，然后根据各区域的孔缝特征和流动机制建立了多区域耦合的渗流模型，并采用PEBI网格和有限体积法进行数值求解。利用数值模拟，分析了连通渗透率和激动量等因素对于干扰试井测试结果及压力场分布特征的影响，并以焦页7井组中的JY7-1 HF井和JY7-2 HF井为例，采用干扰测试压力拟合法计算了两井之间连通段的平均渗透率为18.5 mD，说明两井之间连通性较好，建议后期生产过程中控制本井与邻井的产气量，同时避免邻井频繁更换工作制度。未来井网部署时应根据单井设计产能，对于与邻井水平段距离较近层段应控制压裂规模，并适时开展干扰试井测试。

Multi-stage fracturing horizontal well interference test model and its application

After the large-scale development of horizontal wells and well networks in shale gas fields, the problem of "fast pressure drop and premature gas well abandonment" caused by inter-well interference has become increasingly serious. It is urgent to understand the transient pressure of multi-stage fracturing horizontal wells under interference from adjacent wells and seepage characteristics. For this purpose, the shale reservoirs after multi-stage fracturing reformation of horizontal wells were firstly divided into three areas:fracturing fractures, SRVs and unmodified substrates. Then multi-zone coupled seepage model was established according to the characteristics of the pores in each region and the flow mechanism, and the model was numerically solved by using the PEBI grid and finite volume method. Through numerical simulation, the influences of factors such as connected permeability and agitation on the test results and pressure field distribution characteristics of interference wells were analyzed. Taking JY7-1 HF well and JY7-2 HF well in Jiaoyan 7 well group as examples, the average permeability of the connecting section between the two wells was 18.5 mD, which was calculated by interference test pressure fitting method, showing good connectivity. It is recommended that the gas production should be controlled in the later production process, while avoiding frequent replacement of working systems in adjacent wells. In the future, well pattern deployment should be based on the design productivity of a single well. The fracturing scale should be controlled for the interval close to the horizontal section of the adjacent wells, and the interference well test should be conducted in due course.