Analysis of Wellbore Stability Management and Surveying Time When Using MWD Survey RPM on Cessation Method in Drilling Operations

摘要

This paper explores various case studies to evaluate how an innovative methodology for sending MWDrnsurveys up hole, based on cessation of surface RPM rather than variations of mud flow rate, helps drillingrnoperations become more cost effective, decreasing wellbore stability & HSE risks, reducing surveyingrntime and optimizing connection procedures.rnConventional surveys are taken by recycling the mud pumps. Mud flow is brought to below the MWDrnturn-on rate in order to switch off the tool and trigger the survey, and then the flow is increased to abovernthe turn-on rate and the survey is sent to surface. Surveys based on RPM cessation use a differentrntechnique that allows the MWD tool to take the survey and to transmit it to the surface acquision systemrnwhen it detects that the rotation has being stopped, allowing the mud flow to remain unchanged andrnremoving the need to recycle the pumps.rnVarious distinct applications were analyzed in terms of MWD surveying time, wellbore stability andrnstuck pipe risks to evaluate the impact of this new approach in drilling operations. The cases analyzed dealrnwith the following aspects: reduction of stuck pipe events in projects with high risk wellbore stabilityrnissues, ECD and pressure management in MPD projects, anti-collision avoidance and overall reduction ofrnrig time for projects taking MWD surveys before connection.rnIt was concluded that more and more phases of a well construction have seen the benefit of thisrnmethodology as it has greatly contributed to the efficiency of drilling operations and in some of the casesrnallowing the fulfillment of the well objectives by the significant reduction of drilling risks, in comparisonrnwith the conventional way to take MWD surveys.rnThis is a novel approach to take MWD surveys and send them up-hole; very little has been written inrnindustry literature about how its application enhances the reduction of key drilling challenges such asrnreduction of stuck pipe events. This will allow operators and contractors to push the envelope even further,rnin scenarios where extra fluctuations in the mud flow are adding significant financial or HSE risks.