基于灰色关联分析的产能指数在储集层评价中的应用

Application of productivity index based on grey correlation analysis in reservoir evaluation

储集层含油性、物性是储集层流体性质解释评价的基础,由于含油气性、物性等相关单项资料的局限性,每项资料对解释所做的贡献不同,传统的单一参数已不能满足油气层精细解释评价的需求,将多种资料有效结合、综合应用是进行有效解释评价的基础,数学统计方法成为多参数综合分析必要手段,由此建立了产能指数评价图板。产能指数的确定取决于含油性以及物性数据对该指数的贡献率,即参与该指数计算的各个参数的权重系数。以华北油田霸县凹陷东部文安斜坡区储集层解释评价中的气测全烃、岩石热解含油气总量、定量荧光相当油含量、渗透率和孔隙度5项反映含油性和物性的参数为依据,应用灰色关联分析原理,在分析各个参数关联系数的基础上,得出了产能指数计算的关系式;以该区已试油的8口井18个层录井数据和试油结果为依据,在分别计算出产能指数后,制作产能指数与试油产量交会图板,从中可以看出,产能指数大于0.3为产能区,小于0.3为非产能区。该区两口井的应用表明,预测结果与试油结果相符,避免了常规解释评价中的多解性、差异性、交叉性,提高了储集层解释评价准确性。

Oil-bearing property content and physical property of reservoirs are the bases for the interpretation and evaluation of reservoir fluid properties.Due to the limitation of individual data such as oil and gas properties and physical properties,each data contribution to the interpretation is different.The traditional single parameter can not meet the requirements of fine interpretation and evaluation of oil and gas layes.How to combine many kinds of data effectively and how to comprehensively use are the bases of effective interpretation and evaluation.The mathematical statistics method has become the necessary means for the comprehensive analysis on multiple parameters,therefore,the evaluation chart for the productivity index was established.The determination of productivity index depends on the contribution of oil bearing and physical property data to the index,that is,the weight coefficient of each parameter involved in the index calculation.Taking gas logging total hydrocarbon,total hydrocarbon content of rock pyrolysis,equivalent oil content of quantitative fluorescence,permeability and porosity which were obtained from interpreting and evaluating the reservoirs in Wen′an slope area in the east of Baxian sag,Huabei Oilfield and can reflect oil-bearing property and physical property parameters as the bases,based on the analysis of the correlation coefficient of each parameter,the relation formula of productivity index was obtained by applying the principle of grey correlation analysis.Based on mud logging data and oil test results of 18 layers from 8 wells,after calculating productivity index respectively,the cross plot between productivity index and test oil yield was drawn,from which we can see that the capacity index greater than 0.3 is production area,less than 0.3 is the non-production area.The application of two wells in this area showed that the predicted results were consistent with the oil test results.It avoided the multiple solution,difference and crossover in the conventional interpretation and evaluation,and improved accuracy of the reservoir interpretation and evaluation.