非均质低渗透气藏储层动用能力及影响因素研究

STUDY ON PRODUCING ABILITY OF RESERVOIRS AND INFLUENCE FACTORS IN HETEROGENEOUS

在我国已发现的低渗透气藏中, 类储层占有相当大的比例。苏里格气藏作为一个拥有5000多亿m3储量的特大型气藏, 类储层的储量在总储量中占到40%以上,这部分储量在气田开发中能否动用,动用的程度有多大,对气井产能的贡献有多少,是气田开发中急待解决的问题,而且对气田的产能规划和投资决策影响巨大。利用苏里格气田某气井实际资料,建立了单井地质模型,采用数值模拟技术,对低渗透气藏 类储层的动用能力及影响因素进行了全面的模拟研究,详细分析了不同开采阶段 类储层的动用能力及对产能的贡献。研究表明:低渗气藏 类储层的动用能力与其自身渗透率和含气饱和度以及储层应力敏感性、井附近渗透率、气井初期配产、是否间隙开井等多种因素有关。提出了提高储层储量动用程度的有效措施和相应的开发策略。

In the low-permeability gas reservoirs discovered in our country, the most are the Ⅲ reservoirs. Sulige is a oversize gas reservoir which has over 5,000 a hundred million reserves, the reserves of the Ⅲ reservoirs take up 40% of it's total reserves. Can the reserves be produced? How much is the length of producing? How much is the contribution to gas productivity? These are the problems that are urgent to be solved in gas field developing. It affects the productivity plan of gas field and the decision-making of investment seriously. In this paper, a gas well practical data in Sulige gas field are used to found a geological model of single well, and the producing ability of the Ⅲ reservoirs in low-permeability gas reservoir and the influence factors are simulated entirely. The producing ability of the Ⅲ reservoirs in different recovery moment and the contribution to productivity are analyzed in detail. The Results of the research indicates that many factors are relative to the producing ability of the Ⅲ reservoirs in low-permeability gas reservoir, such as: it's permeability and gas saturation and reservoir stress sensitivity, the permeability near the well, the preliminary allocation of gas well, intermittent production or not, and so on. In the paper, the effective measure and the corresponding development strategy to improve the length of reserves producing are mentioned. It has the important instructional meaning to the productivity planning and the plan design of low-permeability gas reservoir.