校准测试闭合后压降分析

Analysis after closure with calibration test

水力压裂是提高油藏开发效益的最有效手段之一。在压裂设计过程中,需提供储层物性、岩石性质、流体性质等相关参数才能准确地确定压裂施工参数。但对于新区或压裂候选井未生产,因为缺少准确的储层物性参数,例如储层压力、渗透率、滤失系数等,往往要借助小型压裂测试来求取,而通过分析小型压裂测试闭合前的压力数据确定的储层参数,结果与实际情况相比往往误差较大。为提高储层参数的精确度,文中建立了闭合后径向流、线性流数学模型,对公式进行推导求解后,得到了通过对校准测试闭合后压力分析求解储层渗透率、储层压力、初滤失系数这3个储层参数的方法。通过分析实例井压裂测试的压力数据,计算出3个参数值,验证了该方法的准确性。

Hydraulic fracturing is one of the most effective methods to improve the effectiveness of reservoir development. In the fracturing designing process, we need to provide reservoir properties： rock properties, fluid properties and other relevant parameters in order to accurately determine the fraeturing construetion parameter. But in the new discovered area or the candidate wells to be fractured, production is not proceeded, mini-frac test is needed to obtain the required parameters for massive hydraulic fracture such as reservoir pressure, permeability, fihration coefficient, etc. The reservoir parameters determined through the analysis of pressure data before fracture closure usually have greater error to actual situation. In order to increase the accuracy of required reservoir parameters, the pressure data after fraeture closure is used. The mathematic models for linear flow or radial flow after fracture closure are built. According to the solution of the formulas derivation, method using the calibration tests pressure data ＇after fracture closure to determine the permeability, reservoir pressure and spurt coefficient is proposed. Through the analysis of pressure data of fracturing test in case wells, three parameter values have been calculated and the aceuraey of this method has been demonstrated.