基于地化轻烃资料的复杂流体识别方法——以西湖凹陷为例  

Identification methods of complex fluids based on geochemical light hydrocarbon data:Taking Xihu Depression as an example

作　　者：曹英权 王雷 袁胜斌 杨毅 于喜 景社 CAO Yingquan;WANG Lei;YUAN Shengbin;YANG Yi;YU Xi;JING She(China France Bohai Geoservices Co.,Ltd.,Tianjin 300457,China;CNOOC China Limited Shanghai Company,Shanghai 200050,China)

机构地区：[1]中法渤海地质服务有限公司,天津市300457 [2]中海石油(中国)有限公司上海分公司

出　　处：《录井工程》2024年第4期84-90,共7页Mud Logging Engineering

基　　金：中国海洋石油有限公司“十四五”重大科技项目“海上深层/超深层油气勘探技术”(编号:KJGG2022-0405)。

摘　　要：针对西湖凹陷储层流体性质复杂、现场数据受油基钻井液影响,致使解释评价符合率较低的问题,在深入挖掘地化轻烃谱图和数据的基础上,建立了基于轻烃谱图形态与衍生敏感参数的复杂流体识别方法,并进行了应用验证。研究表明:(1)基于轻烃谱图形态差异性可以识别轻质油层和凝析气层,轻质油层表现为正构烷烃C_(1)-C_9组分较为齐全,部分异构烷烃、环烷烃、芳香烃峰值较高且出峰齐全,凝析气层表现为C_(5)以后正构烷烃缺失,异构烷烃、环烷烃、芳香烃含量检测范围较少,峰值较低且出峰不全;(2)通过优选反映轻质油层和凝析气层轻烃检测组分差异性的I_(g)(气指数)、I_(o)(油指数)、∑(C_(1)-C_(5))(含气性指数)和∑(nC_(6)-nC_(8))(含油性指数)建立油气识别图板,可以有效区分轻质油层和凝析气层;(3)基于不同烃组分在水中溶解度的差异性,优选轻烃参数苯、甲苯、环己烷、甲基环己烷建立含水性评价图板,可以判断储层的含水性。该方法在西湖凹陷复杂储层流体的随钻评价中应用,解释符合率可达88%以上,具有较好的推广应用前景。In view of the low coincidence rate of reservoir interpretation and evaluation caused by the complex fluid properties and the influence of oil-based drilling fluid on field data in Xihu Depression,based on in-depth excavation of geochemical light hydrocarbon spectrogram and data,the complex fluid identification methods based on light hydrocarbon spectrogram shape and derived sensitive parameters are established,and have been verified by application.The results are obtained in three aspects.First,light oil layers and condensate gas layers can be identified based on the differences in light hydrocarbon spectrogram shapes.The former shows that the C_(1)-C_(9)components of normal alkanes are relatively complete,and some isoalkanes,cycloalkanes,and aromatic hydrocarbons have complete and higher peaks.The latter shows that the normal alkanes after C_(5)are missing,the detection range for the content of isoalkanes,cycloalkanes,and aromatic hydrocarbons is less,and the peaks are incomplete and the peak values are low.Second,by optimizing I_(g)(gas index),I_(o)(oil index),∑(C_(1)-C_(5))(gas-bearing index)and∑(nC_(6)-nC_(8))(oil-bearing index)that reflect the differences in light hydrocarbon detection components between light oil layers and condensate gas layers,the oil and gas identification chart has been established,which can effectively distinguish light oil layers and condensate gas layers.Third,based on the differences in solubility of different hydrocarbon components in water,the light hydrocarbon parameters of benzene,toluene,cyclohexane,and methylcyclohexane are optimized to establish a water content evaluation chart,which can determine the water content of the reservoirs.The methods are applied to the complex fluid evaluation while drilling of reservoirs in Xihu Depression,and the interpretation coincidence rate can reach more than 88%,which has good prospects for popularization and application.

关 键 词：复杂流体 地化轻烃录井 解释评价 轻质油层 凝析气层 含水性 西湖凹陷 

分 类 号：TE132.1[石油与天然气工程—油气勘探]