随钻伽马能谱录井技术在准噶尔盆地的研究与应用

Research and application of natural gamma-ray spectral logging while drilling in Junggar Basin

为解决准噶尔盆地石油勘探开发过程中地层评价难题,针对完井后不进行测井作业或钻井中由于工程复杂导致无法进行测井的情况,引进随钻伽马能谱录井技术,采用伽马能谱岩性识别方法,对地层进行及时精准的划分,通过曲线对比、数据分析,对地层中放射性元素含量进行测定,建立了分区域、分层位的岩性识别标准,进行地层岩性的精细解释、地层剖面刻画、沉积环境与生油岩评价以及解决油田开发中更多的地质问题.随钻伽马能谱总伽马值与自然伽马测井总伽马值平均相关性达到了0.813.在准噶尔盆地的油气钻探开发中随钻伽马能谱录井技术已在8口重点井进行研究与应用,目前卡层成功率100%,岩性识别符合率84.5%,现场应用取得了良好的效果.

In order to solve the formation evaluation problems in the process of petroleum exploration and development in Junggar Basin,natural gamma-ray spectral logging while drilling was introduced in view of the situation that logging operation is not conducted after well completion or cannot be conducted due to the complexity of engineering during drilling.The gamma spectrometry lithology identification method is adopted to divide the strata timely and accurately.Through curve comparison and data analysis,the content of radioactive elements in the strata is measured,the lithology identification standards of subregion and zonation are established,so as to carry out fine interpretation of formation lithology,stratigraphic profile characterization,evaluation of sedimentary environment and source rock,and solve more geologic problems in oilfield development.The average correlation between the total gamma ray value of natural gamma-ray spectral logging while drilling and the total gamma ray value of natural gamma logging reached 0.813.In the oil and gas drilling and development of Junggar Basin,natural gamma-ray spectral logging while drilling has been researched and applied in eight key wells.At present,the success rate of layer determination is 100%and the coincidence rate of lithology identification is 84.5%,the field application has achieved good results.