准噶尔盆地南缘区块油基钻井液条件下录井技术的选取

Selection of mud logging technology under the oil-based drilling fluid condition in the southern margin block of Junggar Basin

在准噶尔盆地南缘区块,油基钻井液以其良好的润滑性、抑制性在稳定井壁、防止地层水敏性膨胀及钻井提速方面,得到越来越广泛的使用。油基钻井液对传统录井影响很大,特别是对岩屑中荧光显示识别具有较大困难。地化录井技术、三维定量荧光技术、核磁共振技术、显微荧光薄片技术在水基钻井液条件下对于油气显示识别、原油性质判断、流体性质识别等具有重要意义,但在油基钻井液条件下受到较大影响。为了消除或减少油基钻井液对录井的影响,得到较可靠的录井解释评价结论,就如何在油基钻井液条件下准确识别出地层油气显示,总结了一系列录井技术识别手段,后期试油结论验证表明,油气显示发现率达到100%,流体性质判别准确率100%,解释评价准确率77.78%,该方法为油基钻井液条件下录井技术的有效识别油气层提供了可靠依据。

In the southern margin block of Junggar Basin,oil-based drilling fluid has been more and more widely used in stabilizing the borehole wall,preventing formation water sensitive expansion and improving the drilling speed with its good lubricity and inhibition.Oil-based drilling fluid has a great impact on traditional mud logging,especially on the identification of fluorescence display in rock cuttings.Geochemical logging technology,3D quantitative fluorescence technology,NMR technology and microfluorescence thin section technology are of great significance for the identification of oil-gas shows,oil property judgment and fluid property identification under the water-based drilling fluid condition,but they are greatly affected under the oil-based drilling fluid condition.In order to eliminate or reduce the influence of oil-based drilling fluid on mud logging and obtain reliable mud logging interpretation and evaluation conclusions,a series of mud logging technology identification means are summarized on how to accurately identify the strata oil-gas shows under the oil-based drilling fluid condition.The later oil testing results show that the discovery rate of oil-gas shows is up to 100%,the accurate rate of fluid property discrimination is 100%,and the accuracy of interpretation and evaluation is 77.78%.This method provides a reliable basis for the effective identification of hydrocarben reservoir by mud logging technology under oil-based drilling fluid condition.