This article is a practical sequel of the previous paper published in Oil Industry Journal in March 2021. In the previous publication authors considered the theoretical basis for using drilling mechanics parameters to predict porosity and density on the bit by calculating indicator function (rock hardness) through the drilling mechanics parameters and following function calibration in well conditions on the results of well log data (porosity and bulk density).
The present article is based on the results of technology practical testing during the geosteering of the horizontal wells. In a generalized form, the results of applying the technology for forecasting porosity and lithology on the bit based on drilling mechanics data are considered. It is shown that the accuracy of the forecast depends on the type of well path. In total four generalized types were considered: ascending, descending, horizontal, and wavy ("snake"). Approbation is carried out on groups of layers AS, BS, YUS. The main focus of the paper is on the accuracy of the convergence of rock porosity and lithology according to drilling mechanics and well logging data. Some practical explanations are given. It also outlines the difficulties that the authors encountered when introducing the technology into the production process of well geosteering. Two cases are considered in detail. On these examples we step by step analyze drilling mechanics calculations, well logging data, decisions made by the geosteering engineer during the process of drilling support, as well as and achieved drilling efficiency.
References
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