学术论文

      油基钻井液条件下油层的NMR 判识方法

      Oil Layer Identification by NMR with the Use of Oil-Based Drilling Fluid

      摘要:
      油基钻井液具有润滑性好、抑制性强等特点,有利于井壁稳定和油气层保护,在非常规油气水平井及深井、超深井中广泛使用。但是,油基钻井液具有较强的荧光背景和全烃基值,岩屑难以洗出本色,地层油与钻井液的基础油融合,给油层的识别和评价带来了严重影响。为此,创新采用高分辨率低场核磁共振技术随钻监测钻井液含油率及含油性的变化。室内实验结果表明,油基钻井液不同于混油钻井液,后者属于水包油体系,钻遇油层后,在钻井液 T2谱上出现新峰;而前者属于油包水体系,钻遇油层后,在钻井液 T2谱上不出现新峰,但可通过含油性的变化识别重质油层,通过含油率的变化识别轻-中质油层,并在S903H井全油基钻井液及极端的地质条件下取得了较好的应用效果,证明了钻井液核磁共振是油基钻井液条件下一项有效的油层识别技术。
      Abstract:
      Oil-based drilling fluids show advantages such as high shale inhibition and good lubrication, and are beneficial for borehole stability and protecting the oil layers in unconventional horizontal and deep wells. However, oil-based drilling fluids often have strong fluorescent signals and high total hydrocarbon ratio, such that it is difficult to wash the rock debris clean when these fluids are used, resulting in contamination of oil in the layer and making identification and evaluation of oil layers problematic. In this work, high-resolution low-field NMR while drilling was used to monitor the oil content in drilling fluids.The results showed that oil-based drilling fluids had different NMR characteristics from mixed drilling fluids. The latter is an oil-in-water system, such that the new peaks would arise in theT2 spectrum when drilling into oil layer. The former is a water-in-oil system, and no new peaks would arise in theT2 spectrum when drilling into the oil layer. Under such circumstance, however, heavy oil could be identified via oil characterization, and middle and light oil could be determined by analyzing oil content in the oil layer. This method proposed was applied in Well S903H with complex geology and the use of oil-based drilling fluid. It was proved that drilling fluid NMR technique an effective method for identifying oil layers.
      作者: 王志战 [1] 魏杨旭 [2] 秦黎明 [1] 郑奕挺 [1] 赵明 [3] 向蜀平 [3] 惠成峰 [4]
      Author: WANG Zhi-zhan [1] WEI Yang-xu [2] QIN Li-ming [1] ZHENG Yi-ting [1] ZHAO Ming [3] XIANG Shu-ping [3] HUI Cheng-feng [4]
      作者单位: 中国石化石油工程技术研究院测录井研究所,北京,100101 西安石油大学地球科学与工程学院,陕西西安,710065 中石化西北油田分公司勘探项目管理部,新疆乌鲁木齐,830011 中石化华北石油工程有限公司录井分公司,河南郑州,450042
      刊 名: 波谱学杂志 ISTICPKU
      年,卷(期): 2015, (3)
      分类号: O482.53
      机标分类号: TE2 P61
      在线出版日期: 2015年9月16日
      基金项目: 中石化石油工程技术服务有限公司资助项目(JSG11018).