The success of the horizontal well construction process is determined at the planning stage and depends on the speed of making technological decisions during the drilling process, based on comprehensive information that allows minimizing the risks of accidents and complications. Understanding the condition of the wellbore is extremely important, due to the severity of the consequences of the risks associated with it, however, today the degree of uncertainty in terms of wellbore contamination still forms the main statistics of wasted time and money and is a limiting factor in the use of many promising technologies. The purpose of the work is to describe a method for assessing the mud content of a wellbore, which allows, during well drilling, to quickly obtain information about the presence of mud in the wellbore, and to minimize the risks associated with it. Based on the analysis of drilling a large number of wells and performing technological operations to prepare wellbores for lowering casing strings and liners, patterns were identified that made it possible to step-by-step develop and improve a method for assessing the mud content of a wellbore. The analysis of historical data from 90 wells showed the statistical significance of S-standard deviation or standard deviation of the weight on the hook when lifting the bottom hole assembly without circulation and rotation, lying the basis of the method for assessing the sludge content of a wellbore, on the range of fluctuations in the weight on the hook when lowering casing strings and liners. This also confirms the applicability of the hypothesis for assessing the mud content of the wellbore to significantly reduce the risks of performing technological operations when drilling horizontal wells. This topic is given high significance by the general trend in the industry towards increasing the length of horizontal wellbores, increasing the complexity of the used completion assemblies (for example, increasing the number of behind-the-casing packers) and reducing the permissible estimated residual weight on the hook when running completion assemblies (liners), and especially when constructing multilateral wells using TAML technology.
References
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