轻烃录井技术在苏里格天然气储集层解释评价中的应用

Light hydrocarbon logging technology in Sulige gas reservoir interpretation and evaluation

苏里格气田是全国天然气的主要产区之一,鉴于该区气田边界及规模尚不明确,气水分布规律也较复杂,对主力产气层盒8段、山1段、马五段储集层的含水性难以识别。考虑到轻烃录井技术能够更加准确地检测出天然气储集层中各组分含量,尤其是检测C_1-C_5比气测录井更加准确灵敏,首先利用轻烃谱图对储集层类型进行初步的定性判断,再通过对轻烃参数的分析筛选出该地区含气储集层流体性质识别的多项标志性参数,如全烃、烃指数、苯、甲苯等8个参数,基于这些参数与储集层类型相关性的普遍规律,从中优选出C_3/(C_4+C_5)和[C_3/(C_4+C_5)]∑C_(1-5)两参数,并分层系建立了轻烃解释图板。通过综合运用轻烃谱图、标志性参数、轻烃图板等轻烃解释方法,已经实现半定量判断天然气储集层的流体性质,从而有效地识别天然气储集层的含水性,提高了录井解释评价符合率,为后期的勘探开发提供了更可靠的依据。

Sulige Gasfield is one of the main natural gas production areas of the country.In view of unclear boundary and scale in the gas field,gas and water distribution is also complex,the water-bearing properties for major gas production members of He 8,Shan 1and Ma 5are difficult to identify.Considering that the medium-light hydrocarbon logging technology can more accurately detect component parameters of gas reservoirs,especially the detection of C_1-C_5 is more accurate and sensitive than gas logging,use light hydrocarbon chromatogram to carry on the preliminary qualitative judgments on reservoir types,and then through the analysis of light hydrocarbon parameters,select out multi reference parameters for fluid property identification of the regional gas reservoirs,such as eight parameters of total hydrocarbon,hydrocarbon index,benzene,toluene and so on,based on common laws of these parameters and reservoir type correlation,the authors optimized two parameters of C_3/(C_4+C_5)and[(C_3/(C_4+C_5)](C_1-C_5),and established light hydrocarbons interpretation chart by stratification.Through the integrated use of the light hydrocarbon interpretation methods,such as light hydrocarbon chromatogram,characteristic parameters,light hydrocarbon charts,the semi-quantitative judgment for the reservoir fluid properties has been realized,thus the gas reservoir water-bearing property can be effectively identified,the methods improved the coincidence rate of mud logging interpretation and evaluation,and provided a more reliable basis for later exploration and development.