苏里格致密砂岩气田水平井开发地质目标优选

水平井技术是提高致密气单井产量、实现致密气经济有效开发的关键技术之一，与国外致密砂岩气田稳定分布的储层条件相比，国内致密砂岩气田一般具有储层规模小、纵向多层、整体分散及局部相对富集等特点，水平井开发地质目标优选是实现国内致密砂岩气田水平井规模化应用的关键技术问题。以国内典型致密砂岩气田苏里格气田为例，通过实钻水平井地质综合分析和密井网区精细地质解剖，应用储层构型层次分析方法，根据砂体及有效砂体叠置样式的不同，将苏里格气田水平井划分为3个大类6个小类水平井钻遇储层地质模型:A₁垂向切割叠置型、A₂侧向切割叠置型、B₁夹层堆积叠置型、B₂隔层堆积叠置型、C₁单层孤立型、C₂横向串联型。其中分布在辫状河体系叠置带内的A₁垂向切割叠置型和B₁夹层堆积叠置型是水平井开发的主要地质目标。依据储层地质、生产动态、储量丰度、井网密度等关键参数，建立了水平井整体开发和甜点式开发2种开发模式下的井位优选标准，并成功应用于苏中X区块，取得了较好的应用效果，同时该地质目标优选方法与井位优选标准对我国同类气藏的开发具有很好的借鉴作用。

Geological target optimization for horizontal well development of tight sand gas,Sulige Gasfield,Ordos Basin,China

Horizontal well technique is one of the key techniques for production increasing and economic effective development of tight gas. Compared with abroad tight sand gas with stably distributed reservoir,domestic tight sand gas is characterized by small scale reservoir,vertically multi-layered,overall scattered,and locally concentrated. And the optimization of geological target for horizontal well development is the key technical issues for large-scale application of horizontal well in domestic tight sand gas. Taking typical domestic tight sand gas-“Sulige Gasfiled” as an example,through comprehensive geological analysis of drilled horizontal wells and fine geology anatomy of vertical wells in area with a dense well network,with method of reservoir architectural analysis,3 categories and 6 subcategories of drilled reservoir geologic models of horizontal well in Sulige Gasfiled were identified based on the differences of stacking pattern of sandbody and effective sandbody:A₁ vertically cut stacking,A₂ laterally cut stacking,B₁ accumulated stacking with interlayer,B₂ accumulated stacking with barrier,C₁ isolated single layer,C₂ laterally serial layer.A₁ vertically cut stacking andB₁ accumulated stacking with interlayer,all distributed in the superposition lithofacies of braided river systems,and are main geological target of subsequent horizontal well development. According to some key parameters,such as reservoir geology,production performance,reserve abundance,well density and so on,horizontal well site optimizations standard under different development models,which are global development and local development,were built up,and this standard hasbeen successfully applied into the horizontal well development in block X of Suzhong area.Such optimization method of geological target and horizontal well site optimizations standard could provide a good reference for the development of similar gas reservoir in China.