气测标志层比值法在松辽盆地南部让字井地区油层评价中的应用

Application of ratioing technique for gas logging reference lamina to reservoir evaluation in Rangzijing area,southern Songli-ao Basin

气测录井的优势和作用显而易见,但气测数据的环境影响因素校正问题,制约了储集层解释评价纵横向的可比性,不利于解释标准的建立。松辽盆地南部让字井地区中浅层泉四段扶余油层是吉林油田主要的含油层系之一,由于该区含油储集层气油比偏低、重烃含量很低,再加上烃源岩背景气活跃以及工程因素的影响,始终没有建立起有效的气测解释评价油水层标准。鉴于松辽盆地南部中浅层烃源岩———青一段泥岩层分布广泛且稳定,尝试利用青一段泥岩层作为标志层,应用泉四段显示层气测全烃及甲烷最大值分别与该标志层气测全烃及甲烷最大值之比值,来消除环境因素对气测值纵横向可比性的影响,针对让字井地区建立了气测评价图板,即气测显示层全烃和甲烷分别与标志层全烃和甲烷比值法图板。实践应用表明,气测解释评价符合率有了较大幅度提高,效果较好。

Gas logging′s advantage and its role are obvious,but the correction of environmental factors in gas logging data restricts the vertical and horizontal comparability of reservoir interpretation and evaluation and is not conducive to the establishment of interpretation standards.Quan 4th Member of Fuyu oil layer for middle or shallow depth in Rangzijing area of southern Songliao Basin is one of the major oil-bearing series in Jilin Oilfield,as the gas-oil ratio of oil bearing reservoir is low and heavy hydrocarbon content is very low,coupled with active background gas of hydrocarbon source rock and some engineering factors,there have not established any effective standards on gas logging interpretation and evaluation for oil and water layers.Given hydrocarbon source rock of middle or shallow depth,that is,mudstone in Qing1Member in southern Songliao Basin-Qing1 Shale is widespread and stable,mudstone in Qing1 Member was tried to use as a reference lamina,using the ratios of total hydrocarbon of show layer in Quan4 Member to total hydrocarbon of the reference lamina and Methane maximum of show layer in Quan4Member to Methane maximum of the reference lamina to eliminate environmental factors on the vertical and horizontal comparability of gas logging values.A gas logging evaluation chart of Rangzijing area was established,that is the ratioing technique chart of the ratios of total hydrocarbon in show layer to total hydrocarbon in reference lamina and methane in show layer to methane in reference lamina.The practical application showed that the coincidence rate of gas logging interpretation and evaluation has been a substantial increase.