神木气田低渗致密储层特征与水平井开发评价

鄂尔多斯盆地东部神木气田是长庆气区目前增储上产的重要组成部分，系统研究其储层特征、空间叠置结构及水平井开发适用性对气田科学开发具有重要意义。实验分析表明，神木气田山西、太原组储层岩石类型主要为岩屑石英砂岩、岩屑砂岩及石英砂岩，孔隙类型以溶蚀孔、晶间孔及粒间孔为主，储层孔隙度分布于2.0%~10.0%，平均为6.6%，渗透率分布于0.10~1.00 mD，平均为0.83 mD，整体属低孔、致密砂岩储层。测试分析表明，孔隙度5.0%、渗透率0.10 mD、含气饱和度45%为有效储层物性下限标准。基于密井网解剖，将有效砂体空间结构类型划分为多层孤立分散型、垂向多期叠加型、侧向多期叠置型等3种。研究表明，神木气田不适合开展大规模水平井开发，可在有限地区进行局部式水平井部署。

The Characteristics of the Low Permeability Tight Reservoir in the Shenmu Gas Field and the Evaluation of Horizontal Well Development

The Shenmu Gas Field located in the east of the Ordos Basin is a major component of the reservoir and production of gas in the Changqing gas zone. A systematic analysis of the reservoir characteristics, the spatial superposition structure, and the applicability of horizontal well development is of significance in the scientific development of the gas field. The experimental analysis shows that the reservoir rocks in Shanxi and Taiyuan Formation in Shenmu Gas Field are mainly lithic quartz sandstone, lithic sandstone, and quartz sandstone. The pores in the rocks are mainly dissolution pores, intercrystalline pores, and intergranular pores. The porosity of the reservoir ranges from 20% to 10.0% with an average value of 6.6%, while the permeability of the reservoir ranges from 0.10 to 1.00 mD with an average value of 0.83 mD. The reservoir can be classified as a low-permeability and tight sandstone reservoir. The results from gas tests show that a porosity of 5%, a permeability of 0.10 mD, and a gas saturation level of 45% is the lower limit of the physical properties for effective reservoir. Based on the dissection of the close well spacing, the effective spatial structure of the sand body is classified into three types:the multi-layer isolated dispersed type, the vertical multi-stage superposition type, and the lateral multi-stage superposition type. The study shows that the Shenmu Gas Field is not suitable for large scale horizontal well development. Local horizontal wells can be deployed in certain regions.