考虑应力敏感性的产能与压差非线性关系

Nonlinear relationship between production capacity and differential pressure
based on stress sensitivity

 李根¹ 李云鹏² 曲炳昌¹ 黄磊¹ 黄建廷¹ 常涛¹

中海石油（中国）有限公司天津分公司，天津 300452 中国石油大港油田分公司勘探开发研究院，天津 300280）

Tianjin Branch of CNOOC Ltd., Tanggu 300452, China Research Institute of Exploration and Development, PetroChina, Dagang Oilfield Company, Dagang 300280, China)

 将岩石应力敏感性代入裘比公式得到新的单井产能计算式，采用同类项消除法，将计算式变形为可由提液前后的压力数据得到提液前后产能比的计算式。将产能比的计算值与实际值代入平方误差函数作为衡量二者接近程度的手段，若改变应力敏感系数对二者接近程度影响很大，则说明应力敏感为该油田产能与压差非线性关系的主要影响因素，同时还能够得到使平方误差函数达到最小的应力敏感系数。采用该方法对埕北油田提液井的产能变化进行了分析，结果表明：高渗透油藏产能同样受制于岩石应力敏感性，得到最优化应力敏感系数后能进一步得到该油田岩心的应力敏感性曲线。

 New calculation formula of well productivity was deduced by substituting the stress sensitivity of rock in Dupuit formula. Using the similar elimination method, the formula was transformed to a new one which makes the user get the productivity ratio from the pressure data corresponding to the pre-after liquid production. Taking the calculated productivity ratio and the actual one into the square error function to calculate the degree of the approximation, if the change of stress sensitivity coefficient has a great influence on the degree of approximation, it is proved that the stress sensitivity is the main factor affecting the nonlinear relationship between productivity and differential pressure in this oil field. At the same time, the stress sensitivity coefficient which minimizes the square error function can be obtained. Using this method to analyze the productivity change in the wells with liquid production increasing in Chengbei Oilfield, the results show that the productivity of high permeability reservoir is also controlled by the rock stress sensitivity, and the stress sensitivity curve of the core can be further obtained after calculating the optimized stress sensitivity coefficient.

10.6056/dkyqt201704020