苏里格气田苏S区块高含水气藏气水识别及开发对策研究

Study on gas-water identification and development strategy of high water-cut gas reservoir in Su S block of Sulige Gas Field

针对苏S区块中部区域储层含气饱和度低、气水关系复杂、部分气井出水严重以及投产成功率低的难题,从气井出水特征入手,开展气水分布规律及分布模式研究,并在常规气水识别的基础上,引入可动水饱和度参数,建立苏S区块中部高含水区可动水饱和度计算模型,制定高含水区不同气水分布模式下储层射孔原则及开发对策。结果表明1)可动水饱和度影响气井生产效果,储层可动水饱和度的大小与产出水状况基本呈正相关关系;2)生烃强度及与源岩距离、储层展布从根本上控制了气水分布格局,而沉积环境、储层物性等因素决定了局部气水分布模式;3)苏某CH井开发山1段25~29号层,可动水饱和度16.0%~33.4%,初期日产气6×104 m^(3),气水比0.7~2.0,取得较好开发效果。实践表明侧钻水平井开发低渗高含水气藏具有一定优势。该研究为实现苏S区块高含水气藏效益开发提供科学依据,对提高苏里格气田采收率、改善气田开发效果、降低开发成本具有指导意义。

Aiming at the problems of low gas saturation,complex gas-water relationship and low success rate of some gas wells in the middle area of Su S block,from the characteristics of the gas well outlet water,gas-water distribution laws and gas-water distribution pattern are studied.On the basis of conventional gas-water identification,movable water saturation parameters are introduced to establish a calculation model of movable water saturation in the middle high water-cut area of Su S block.The perforating principle and development countermeasures under different gas-water distribution modes in high water-cut area are formulated.The results show that:1)Movable water saturation affects gas well production.The higher the movable water saturation is,the higher the gas-water ratio of the corresponding gas well is,the higher the water production is,and the smaller the final accumulated gas produced by a single well is.2)Hydrocarbon generation intensity,distance from source rock and reservoir distribution fundamentally control the distribution pattern of gas and water.The local gas-water distribution pattern is determined by sedimentary environment and reservoir physical properties.3)The 25~29 layers of Shan1 section are developed in well CH of Sumou,with movable water saturation of 16.0%~33.4%and daily gas production 6×104 m^(3),gas water ratio is 0.7~2.0,and good development effect has been achieved.Practice shows that sidetracking horizontal wells have certain advantages in developing low permeability and high water content gas reservoirs.This study provides scientific basis for realizing the efficient development of high water cut gas reservoir in Su S block.This study has guiding significance for improving the recovery rate,improving the development effect and reducing the development cost of Sulige Gas Field.