文88块天然气驱中的气体示踪剂监测技术

Gaseous Tracer Monitoring Technology at Wen88 Block Natural Gas Drive

文88块是利用天然气驱开发的一个典型的异常高压低渗油藏。2006年3月开始在文88-15井、文88-25井2口井注气,为了跟踪和评价气驱井组的动态情况,认识注入井与生产井的受效关系,研发了井间气体示踪剂监测技术,包括气体示踪剂预处理装置,注入设备,气体示踪剂种类、注入工艺及注入量的确定,目前已成功应用于该2井组。文88-25井注气体示踪剂QT-1后,在对应3口生产井连续取气样99天,文88-15井注气体示踪剂QT-2后,在对应2口生产井连续取样152天,由气样分析数据及井参数计算得到突破时间、峰值时间、推进速度、波及面积和体积及高渗带厚度比例系数等参数,据此讨论了各注采井间的连通关系。利用一种示踪剂解释软件,通过地质建模,得到了5口生产井的示踪剂产出拟合曲线,与实测曲线相比,相关性尚好。图5表1参2。

Wen 88 block is a typical abnormal high pressure and low permeability oil reservoir, exploited by natural gas drive tech- nique. The natural gas injection in Wen-88-15 and wen-88-25 wells has started in march 2006. To trace and evaluate the gas drive performance of the two well groups and to ascertain the connection between injection and production wells, a well-to-well tracering technique by using gaseous tracers （GTs） was developed, including pretreatment and injection installations for GTs, species and quan- tity of GT needed and its injecting technology, and was applied successfully in the two wells above mentioned, with GTs QT-1 and QT-2 injected into Wen-88-15 and Wen-88-25 wells, respectively, sampling and analyzing gas samples were made in time duration of 99 days for three production wells of Wen-88-25 well group and of 152 days for two production wells of Wen-88-15 well group. On the basis of gas analysis data and well characteristics, the tracer breakthrough time, the peak of tracer production, the advancing velocity of tracer, its sweeping area and volume, and the thickness proportion factor of highly permeable zones were calculated and the connection between injection and production wells was discussed in terms of these parameters. By using a software for tracer interpretation and by the way of geological modelling, the fitted tracer production curves were constructed for the five production wells and were correlated with real curves fairly well.