气井压裂效果评价及施工因素分析

Evaluation on Gas Well Fracturing Effect and Analysis on its Corstruction Factors

在压裂设计和压后生产之间,压后评价技术是承上启下的中间环节,压后评价技术对压裂技术的改进和压后气井生产经济效益的提高起到了"推进器"的作用。煤层气井通常采用压裂增产,因而压裂评价显得尤为重要。首先证实煤层气井压裂后增产效果显著,再运用裂缝参数计算对比法评价压裂效果。利用压裂施工曲线获取数学模型中所需参数,对裂缝几何参数(缝长、缝宽)进行计算,优选、优化压裂设计参数,并建立简单可行的裂缝参数计算模型,建立的改进模型提高了缝长、缝宽计算的精准率。结合地质因素,从单因子和多因子两个角度,对影响压裂裂缝参数的压裂施工因素进行了分析,认为:一般情形下,施工参数与裂缝参数成正相关,达到一定程度后,相关性就不明显。在此基础上,优化压裂施工参数,为后续的施工设计提供一定依据。

At present, such methods as output estimation, economic evaluation and comparison of fracture parameters are usually used for fracturing effect analysis and such method is used more widely that various mathematical models and test data are applied to calculate geometric parameters of fractures. It is confirmed that production increase effect is obvious after coalbed methane wells are fractured. Applied are the fracturing operation curves to collect parameters needed in mathematical mode calculation, calculated are geometric parameters of fractures(fracture length and width), optimized is the fracturing design parameters, established is a sample and feasible calculation method of fracture parameters and the established improvement model can increase the accuracy of the calculated fracture length and width values. In combination with geological factors, analyzed is effect of fracturing construction factors on fracturing fracture parameters and it is considered that construction parameters is positive correlation with fracturing parameters in general cases and the correlation is not obvious when a certain degree is reached.