Drilling fluid selection due to geological formation in oil andnatural gas drilling

Our country's goal of rising above the level of contemporary civilizations is the energy network established with a strong economy and the availability of demanded raw materials at reasonable cost and with remarkable profitability. A number of studies have been carried out to increase the drilling performance with field and laboratory studies at the point of solving the problems arising from the formation encountered during drilling in hydrocarbon exploration, which is one of the cornerstones of energy. In the study, the most effective intervention recipes were defined separately in order to overcome the well stability problems arising from the formation, since each formation shows different characteristics in different regions. In hydrocarbon drilling studies, well stability, formation pressure and hydrostatic pressure balance are considered as a priority among the problems arising from the formation. Values such as viscosity, density, gel values, fluid loss, clay content and salinity of the drilling fluid for well stability and formation pressure were evaluated during drilling in the field and drilling efficiency was revealed. Methylene blue test (MBT), fluid loss, calcium, alkalinity, Pf, Mf and Pm tests whicj are the amount of tank lime content, sludge weight, rheology, chlorine (Cl) and potassium (K) tests were applied to different samples taken for the formation. It has been determined that the use of carboxy methyl cellulose (CMC LV) in lignosulfonate sludges, starch and poly anionic cellulose (PAC LV) in potassium chloride (KCl) sludges were deemed appropriate. In terms of supporting rheology, good results were obtained by giving chemicals such as xandan (Xcd) and flo-vis plus. As a result of the experiments, it was determined under which conditions the use of chemicals would increase efficiency of drilling fluids. In this context, The viscosity value was reduced from 73 sec/qt to 51 sec/qt, and the sludge weight was increased from 71 ppcf to 72 ppcf despite the formation stability problem, thus preventing collapses in the well. According to the formation cracking pressure, the sludge weight was reduced from 86 ppcf to 85,5 ppcf in order not to cause gradual leakage and full leakage. It was obtained by adding fresh mud to the system and operating the decander (clay separator) actively, while reducing the clay amount from 15 lb/bbl to 11,25 lb/bbl for the increase in the clay ratio detected in the drilling mud.