准噶尔盆地车排子凸起东翼石炭系火山岩储层主控因素定量评价

Quantitative Evaluation of the Main Control Factors of Carboniferous Volcanic Reservoirs in the Eastern Margin of Chepaizi Uplift,Junggar Basin,China

以准噶尔盆地车排子凸起东翼石炭系火山岩储层为研究对象,利用测井、录井、钻井、试油、岩芯、岩屑、薄片等资料,分析研究区火山岩储层主控因素。在此基础上,运用灰色关联分析对储层主控因素进行定量评价;选用油气累积产量作为母因素,与油气累积产量相关性较高的主控因素作为子因素,衡量火山岩储层质量。结果表明:影响车排子凸起石炭系火山岩储层形成的主控因素包括岩性和岩相类型、裂缝发育程度以及风化淋滤作用;通过对各评价参数权重系数计算,风化淋滤作用权重系数最大,为0.271,其次为裂缝密度,权重系数为0.261,最后是岩相和岩性类型,权重系数分别为0.247、0.222;根据储层综合评价指标(IREI)结果,将IREI≥0.6定为Ⅰ类储层,0.3≤IREI<0.6定为Ⅱ类储层。运用该储层定量评价标准对单井储层进行综合评价验证,结果与实际油气累积产量吻合率高达90%;单井储层定量评价分类结果与实际油气累积产量及研究区有利储层平面分布预测吻合度较高,评价结果可靠。

Taking Carboniferous volcanic reservoirs in the eastern margin of Chepaizi uplift,Junggar Basin as research object,the main control factors of the volcanic reservoirs were analyzed by various types of data,including logging,drilling,testing for oil,cores,cuttings and thin sections.The gray correlation analysis was applied to quantitatively evaluate the main control factors of reservoirs;the cumulative oil and gas production was selected as the parent factor,and the main control factors which have high correlation with the cumulative oil and gas production were selected as the sub factors to measure the quality of the volcanic reservoirs.The results show that the main control factors affecting the formation of Carboniferous volcanic reservoirs in Chepaizi uplift include lithology,lithofacies,fracture development,weathering-leaching;by calculating the weight coefficient of each evaluation parameter,the weight coefficient of weathering-leaching is the biggest with the value of 0.271,followed by fracture density with the weight coefficient of 0.261,and the weight coefficients of the lithology and lithofacies are the smallest with the values of 0.222 and 0.247,respectively;the volcanic reservoirs in the study area can be generally divided into two different types based on comprehensive evaluation index(I REI)of reservoirs,as for typeⅠ,the I REI is greater than 0.6,and as for typeⅡ,the I REI ranges from 0.3 to 0.6.The reservoir quantitative evaluation criteria were used to verify the comprehensive classification and evaluation of single well reservoirs,the results coincide with the actual cumulative oil and gas production rate as high as 90%;the quantitative evaluation classification results of single well reservoirs and actual cumulative oil and gas production are in good agreement with the favorable reservoir plane distribution prediction in the study area,the evaluation results are reliable.