致密砂岩气藏气水层识别新方法——以苏76井区为例  

A new method for identifying gas-water layer in tight sandstone gas reservoirs:Case Study of Su76 well area

作　　者：朱文卿[1] 高树生[1] 沈杰 叶礼友[1] 刘华勋[1] Zhu Wen-qing;Gao Shu-sheng;Shen Jie;Ye Li-you;Liu Hua-xun(PetroChina Research Institute of Petroleum Exploration&Development,Langfang 065007,China;The Second Drilling Company of CNPC Bohai Drilling Engineering Company Limited,Langfang 062552,China)

机构地区：[1]中国石油勘探开发研究院,河北廊坊065007 [2]中石油渤海钻探第二钻井公司,河北廊坊062552

出　　处：《天然气地球科学》2019年第11期1629-1638,共10页Natural Gas Geoscience

基　　金：国家科技重大专项”致密砂岩气有效开发评价技术”(编号：2011ZX050130-002)资助

摘　　要：苏76井区位于鄂尔多斯盆地西部,物性明显差于中东部,是含水饱和度高、孔渗极低的致密砂岩气藏,具有产水井比例高、产能低、采收率低的生产特征。为了准确识别气、水层以降低产水风险,将可动水饱和度参数引入到常规气、水层识别中,分析大量的测井解释结果、生产数据及试气结果,建立了气、水层综合识别方法。结果表明,苏76井区储层微观孔隙结构差,微小孔发育,导致储层残余水饱和度高,含气性较差,开发过程中,部分束缚水转化为可动水,仅可动水饱和度能表征水相的流动能力,核磁共振结果表明该区块可动水饱和度低。通过对比分析可动水饱和度测井解释结果与实际试气及生产数据,建立了气水层综合识别方法。通过识别结果可对单井进行产水预测并优选射孔层位,有效降低气井产水风险。在此基础上绘制了区块气水平面分布图,进而优选出低产水风险区,明确气田的主力储层,为气田合理开发提供科学依据。The Su76 well area is located in the western part of the Ordos Basin,and its physical properties are obviously worse than those in the east-central parts. It is a dense sandstone gas reservoir with high water saturation and extremely low porosity. Gas wells generally have the characteristics of high water production ratio,low production capacity and low recovery rate. In order to accurately identify the gas and water layer to reduce the risk of water production,movable water saturation are introduced into the normal gas and water layer identification method,and a comprehensive identification method for gas and water layer is established by analyzing a large number of log interpretation results,production data and gas test results. The results show that the pore structure of the reservoir in Su76 block is poor and the micro pore is developed,resulting in high irreducible water saturation and poor gas bearing. In the process of development,partial bound water is converted into movable water,and movable water saturation can characterize the flow capacity of water phase. Nuclear magnetic resonance results show that the movable water saturation of the block is low;by contrast and analysis between the conventional logging interpretations and practical performance data of the movable water saturation,comprehensive identification method of gas and water layer is established. Through the identification results,the gas production prediction of single well can be carried out,and the perforation layer can be optimized to reduce the water production risk of gas well;Based on the achievements,the gas & water distribution map is drawn foe the study area,therefore the low-risk block of the water production is optimized,the main reservoirs of the gasfield are ensured. The research results have provided a theoretical evidence for the reasonable development of the sandstone gasfield in China.

关 键 词：致密砂岩气藏 苏76井区 产水机理 气水层识别 

分 类 号：TE31[石油与天然气工程—油气田开发工程]