Integrated Approach to Prevent and Mitigate Stuck Pipe in Interbedded Depleted and High Pressure Gas Reservoirs

Abstract

Stuck pipe is one of the main challenges in any drilling operation especially drilling horizontal or deviated wells through deep reservoirs. Stuck pipe occurs while drilling, logging, running casing and running lower completion especially the Multi-Stage Fracturing (MSF) completion string. This causes long non-productive time, limits the drilling performance and increases the well cost. An integrated approach is necessary to eliminate and reduce the stuck pipe occurrence and improve operation efficiency. This integrated approach starts with the planning phase by evaluating the formations characteristics, pressure and stresses across the planned well, and creating the predrill Mechanical Earth Model (MEM) using offset wells information to calibrate it. This allows to anticipate the drilling conditions and the severity of the risk in each well. The drilling fluid and bridging materials are designed based on the formations characteristics, lithology, pore pressure and anticipated pore throat sizes using specific software packages to identify the optimum bridging plan. The drilling, logging, and the completion strings are designed based on the risk type and severity. The operational practices and operating envelope are set based on the downhole anticipated conditions, risk severity and type, hydraulics and hole cleaning simulations. Actual downhole conditions and a reviewed risk level are continuously monitored and fed back in the process: the operational practices, the drilling fluid properties, the bridging materials design and operating envelope are revised and optimized based on the actual wellbore conditions during execution to improve operational efficiency and reduce the stuck pipe risk. The post job evaluation is a crucial part of the process to analyze the efficiency of the implemented actions, to capture lessons learned, and revise and update the integrated approach for continuous improvement. This paper describes the whole integrated approach process together with the results of the implementation carried out in several wells with different profiles and subsurface conditions. It also highlights the successes achieved in stuck pipe prevention and improved operational efficiency.