容积法储量计算中砂体有效厚度高精度成图方法

HIGH-PRECISION MAPPING METHOD OF THE EFFECTIVE THICKNESS FOR THE SANDBODIES IN THE RESERVE CALCULATION BY VOLUMETRIC METHOD

随着渤海浅层河流相油田储层高精度描述技术的不断完善,河流相油田储量计算已由以油组为单元的构造油藏模式转变为以单砂体为单元的岩性油藏模式,对储量计算精度提出了更高要求。基于砂体描述的储量计算,砂体有效厚度是影响计算精度的最关键因素。针对常规方法的不足,提出了一套通过求取砂体内部泥岩夹层厚度进而反求油气层有效厚度的制图方法,有效解决了常规方法中经常出现的油气层有效厚度大于砂体厚度的矛盾,保证了图件精度和储量计算结果的可信度。该方法在BZ油田实际应用取得了良好效果。

With the continuous improvement of the high-precision reservoir describing technique in Bohai shallow fluvial-facies oilfield,the reserve calculations of the oilfield have been changed from the structural reservoir model taking the oil groups as the units into the model composed of the single sandbody unit,thus the higher-precision requirements are needed for the reserve calculations.Based on the calculations of the sandbody description,the effective thicknesses of the sandbodies are the most important calculation influencing factors.In the light of the shortcomings of the traditional methods,a set of the mapping methods were presented for the backward seeking of the oil/gas reservoir effective thicknesses by the mudstone interbed thicknesses within the sandbodies,thus the contradiction is effectively solved for the effective thicknesses of the oil/gas reservoirs greater than those of the sandbodies by the conventional methods,therefore the credibilities of the mapping precision and reserve calculation results are ensured.With the help of the approach,much better oilfield application effects are obtained.