论文部分内容阅读
在建立储层连通性的过程中,储层所固有的不确定性总是油藏管理中存在的问题。鉴于延长生产试验可能费用过高或不可行,使用测井资料、岩心资料和地震资料等相关的标准方法有时并不充分。基于储层流体的组合差异,现在开始越来越多地使用地球化学技术来确定储层的连通性。在世界许多油藏中,CO2是一种关键的气体成分。同一个油田的两个油藏,其中一个位于澳大利亚的Browse盆地,一个位于马来西亚的马来盆地。CO2的含量从一个区域到另一个区域浓度由低到高变化很大。此外,对储层流体试样中CO2精确的定量分析可能比较困难,尤其当采集试样中含水时,其难度会更大,这是由于CO2容易和泥浆滤液或地层水反应的结果。因此,油田水基泥浆(WBM)钻井中,为CO2定量分析所采集的试样应尽可能地减小污染。本文介绍的油田实例均来自亚太地区,此地区已开始使用新一代电缆地层测试器(WFT)和先进的井底流体分析器(DFA)来获取高质量的PVT试样并对CO2进行实时测量。对同一区域的先前勘探井所获得的碳氢化合物进行试样分析,如果分析结果显示出CO2含量发生很大变化时,就必须对取样方法进行改良,改良后的方法使用先进的DFA测量仪器,能够精确地测量流体成分时刻在发生变化的大量储层中的CO2浓度。本文也讨论了不同储层流体变化条件下获取高质量PVT试样所遇到的操作性问题以及所面临的挑战。
In establishing reservoir connectivity, reservoir-specific uncertainties are always problems in reservoir management. In view of the fact that it may be costly or impracticable to prolong a production test, the standard methods associated with logging data, core data and seismic data are sometimes inadequate. Based on the combined differences in reservoir fluids, geochemical techniques are now increasingly being used to determine reservoir connectivity. Among many reservoirs in the world, CO2 is a key gas component. Two reservoirs in the same field, one in the Browse Basin in Australia and the Malay Basin in Malaysia. Concentrations of CO2 vary greatly from low to high from one area to another. In addition, accurate quantitative analysis of CO2 in reservoir fluid samples can be difficult, especially when the sample contains water, which is more difficult because of the reaction of CO2 with mud filtrate or formation water. Therefore, in oilfield water-based mud (WBM) drilling, the samples collected for the quantitative analysis of CO2 should be minimized as much as possible. All of the examples in this paper are from the Asia Pacific region. In this area, a new generation of cable formation testers (WFTs) and state-of-the-art downhole fluid analyzers (DFA) have been used to obtain high quality PVT samples and measure CO2 in real time. Sample analysis of hydrocarbons obtained from previous exploration wells in the same area should be improved if the results of the analysis show significant changes in CO2 content. The improved method uses advanced DFA measuring instruments, It accurately measures the CO2 concentration in a large number of reservoirs where the fluid composition changes. This article also discusses the operational issues and the challenges encountered in obtaining high quality PVT samples under varying reservoir fluid conditions.