PNST剩余油测井对陇东油田的适应性分析  

Applicability Analysis of PNST Remaining Oil Logging to Longdong Oilfield

作　　者：郑华[1] 沈付建[1] 袁立甲 刘开天 李亚娟[1] ZHENG Hua;SHEN Fujian;YUAN Lijia;LIU Kaitian;LI Yajuan(Logging & Testing Services, Daqing Oilfield CO. LTD., CNPC, Daqing, Heilongjiang 163453, China;Oil Production Plant No.2, Changqing Oilfield Company, CNPC, Qingyang, Gansu 745100, China)

机构地区：[1]大庆油田有限责任公司测试技术服务分公司,黑龙江大庆163453 [2]中国石油长庆油田分公司第二采油厂,甘肃庆阳745100

出　　处：《测井技术》2020年第2期151-158,164,共9页Well Logging Technology

基　　金：国家油气重大专项“大型油气田及煤层气开发”(2017ZX05013-005)。

摘　　要：陇东油田侏罗系延安组和三叠系延长组的地层水矿化度较高,这有利于碳氧比、氯能谱、中子寿命、脉冲中子-中子等脉冲中子剩余油测井技术的综合应用,但是储层孔隙度较低,需要研究PNST脉冲中子全谱剩余油测井对该地区的适应性。在陇东油田的产出水含盐10.3~36.2 g/L的6口油井中开展了现场试验。结果显示PNST测井曲线能较好地反映岩性、孔隙度和含水饱和度的变化,但是随着孔隙度降低对饱和度的分辨能力也有所下降。试验井延8、延9、长3和长8储层的平均孔隙度分别为17.7%、16.4%、12.6%和9.4%,PNST的4种饱和度解释值之间的平均方差相应地分别为6.9%、7.1%、9.2%和11.9%。储层水淹状况解释结论与油井产水率的符合率为83%,不相符的主要原因被证实是测井时有较多井液侵入射孔层,推开了井筒附近的剩余油。试验结果表明,在不洗井、不压井的情况下,PNST剩余油测井能适应陇东油田孔隙度低至9%的储层。The salinity of the formation water in the Jurassic Yan’an Formation and Triassic Yanchang Formation in Longdong Oilfield is relatively high,indicating remaining oil logging tools(Pulsed Neutron Spectral Tools(PNST)involving carbon-to-oxygen ratio,chlorine spectra,neutron lifetime,and pulsed neutron-neutron)are favorable.However,since the reservoir porosity is relatively low,it is necessary to test the adaptability of the whole spectra of pulsed neutron in all reservoirs.Field tests were carried out in six oil wells with salinity of produced water ranging from 10.3 g/L to 36.2 g/L in Longdong Oilfield.The results show that the PNST logging curves can reflect changes in lithology,porosity and water saturation quite well.However,as porosity decreases,the resolution of saturation increases.In Wells Yan 8,Yan 9,Chang 3 and Chang 8,the average porosity is 17.7%,16.4%,12.6%,and 9.4%,and correspondingly,the average variance of the PNST saturation is 6.9%,7.1%,9.2%,and 11.9%,respectively.The interpretation of the waterflooded reservoirs coincides with the measured water cut by 83%,and the discrepancy is believed to be the cause that fluid invaded the perforated layers and pushed away the remaining oil near the wellbores while logging.The test results have proved that the PNST remaining oil logging technology is applicable to the reservoirs with porosity as low as 9%in Longdong Oilfield without well washing and well killing.

关 键 词：脉冲中子全谱测井仪 剩余油饱和度 储层评价 油井生产动态 陇东油田 适应性 

分 类 号：P631.84[天文地球—地质矿产勘探]