基于拟稳态时间水平井产能新公式研究及应用

针对低渗透油藏和稠油油藏,水平井技术提高采收率得到广泛应用,而水平井产能的确定是水平井设计和优化的重要依据。海上油田水平井产能确定主要依据周围相似油藏条件下已投产定向井实际产能数据确定水平井米采油指数,结合设计压差和油层厚度计算水平井产能,该方法缺少一定理论基础,同时需要油藏人员具有丰富工作经验;另外一种确定方法是应用Joshi公式计算,该方法要求已知水平井控制半径条件下计算水平井产能,而水平井控制半径的确定具有一定人为性。针对以上两种方法存在的弊端,通过油藏工程方法,应用等值渗流阻力原理和保角变换确定水平井产能公式,同时确定水平井流动形态和控制半径,该方法克服了人为确定水平井半径弊端,根据海上油田已生产井,对产能公式进行验证,确定该公式的准确性,为水平井产能确定提供一定理论基础,对于调整井和新井投产的产能评价具有一定指导意义。

The research and application of new horizontal well productivity formula based on pseudo steady state time

For heavy oil reservoir and low permeability reservoir, horizontal well technology is widely used for enhanced oil recovery. And the determination of horizontal well productivity is the important basis for designing and optimizing horizontal wells. The determination of horizontal well productivity on offshore depends on directional well productivity with similar reservoir conditions, and Jo is calculated. According to differential pressure and reservoir thickness, horizontal well productivity is defined. But this method is the lack of a certain theoretical basis, and needs reservoir personnel has rich work experience. Another method is application Joshi formula calculation, this method requires known control radius, but there are artificially for the determination of control radius. For these disadvantages above two methods, through reservoir engineering method in this paper, the law of equivalent percolation resistance and conformal transformation are used to determine the formula of horizontal wells. And at the same time the flow shape and control radius of horizontal wells are curtained. This method overcome the disadvantage of control radius artificial determined. The formula is verified according to produced wells on offshore reservoir, determines the formula of accuracy. It provides theory basis for the determination of horizontal well productivity, and is the meaning of the guidance for the production evaluation of adjustment wells and new wells.