The Middle Jurassic Shaximiao 1 gas reservoirs,Zitong block,northwestern Sichuan Basin:Exploration and development
In an effort to speed up the productivity construction of tight gas in Sichuan Basin,gas reservoirs of the first member of the Middle Jurassic Shaximiao Formation(Shaximiao 1 Member)in Zitong block of northwestern basin were tak-en as examples to analyze geological and development characteristics.With complex geological conditions,the Shaximiao 1 reservoirs are quite different from the same reservoirs and Shaximiao 2 reservoirs individually in adjacent Jianyang and Jin-qiu blocks.So,it's necessary to make available measures on development technologies through pilot tests.Results show that(i)developed with vertically superimposed multiple-episode channel sandstone,the Shaximiao 1 reservoirs in Zitong block are characterized by poor physical properties,small thickness,and strong heterogeneity;and(ii)there exist numerous pressure systems in these reservoirs with high water saturation,leading to big incidence of water production.In conclusion,Zitong block has a great prospect in natural-gas exploration and development,and will be a remarkably new domain for en-larging reserves and production in the future.Nevertheless,a shortage of static and dynamic data and inadequate under-standing on reservoir geology make it essential to conduct pilot tests.What's more,there massively extended two suits of reservoirs in Zitong block,such as No.1 and No.4 sandbodies superimposed in Shaximiao 1 Member.And industrial gas flow has been received.Both sandbodies are selected as the target in pilot demonstration areas to make clear gas content in them.On top of that,learned from development experience in adjacent blocks,8 horizontal wells with big included an-gle have been deployed and some efficient stimulation technologies have been optimized to establish a geology-engineering integration model,among which the designed output in single well is(6-9)×104 m3/d,and the predicted cumulative pro-duction also in single well of(1.06-1.30)×108 m3,respectively.
万方数据
维普
