塔东古城地区孔洞型含气碳酸盐岩储层孔隙度评价方法研究

Porosity evaluation method for vuggy carbonate reservoirs in the ancient city of East Tarim Basin

塔东古城地区碳酸盐岩储层岩性变化多样,岩石骨架参数难以确定;孔隙空间分布非均质性较强,且储层含气对中子、密度测井有明显影响,导致了孔隙度评价困难。本文针对塔东古城地区孔洞型含气碳酸盐岩储层孔隙度评价核精度较低的问题,在准确计算矿物组分含量的基础上,通过变骨架和中子密度孔隙度组合建立孔隙度模型,消除了碳酸盐岩储层岩性和含气性等影响因素对计算结果的影响,提高了孔洞型含气碳酸盐岩储层孔隙度的计算精度。实际资料处理结果表明,利用该方法计算的孔隙度与岩心分析孔隙度结果符合较好,能够满足储层孔隙度评价精度要求。

The lithology of carbonate reservoir in the ancient city of the east of Tarim is varied, the parameters of the rock skeleton are difficult to be determined, the heterogeneity of the pore space distribution is strong, and the gas content of the reservoir has a obvious influence on the neutron and density logging, which leads to the difficulty in evaluating the porosity. On the basis of accurate calculation of the mineral component content, the porosity model is established by the combination of variable skeleton and neutron density porosity on the basis of accurate calculation of the mineral component content in the ancient city of the ancient city of Tarim, which eliminates the results of the calculation results of the lithology and gas bearing factors of the carbonate reservoir. The calculation accuracy of porosity in gas filled carbonate reservoirs is improved. The results of actual data processing show that the porosity calculated by this method is in good agreement with the result of core analysis porosity, and can meet the requirements of reservoir porosity evaluation accuracy.