New Records of Extended Reach Drilling in China Offshore

Abstract More than just providing an overview of the longest extended reach drilling (ERD) well recently accomplished in China offshore, with a total depth of 9508m and an ERD ratio of 4.46, the paper will delve deep into key elements such as well design, drilling technologies and practices implemented, which contribute to the success of a well that is approaching the limits of feasibility. Post-job learning and thinking will also be discussed. To drill challenging ERD wells, sophisticated engineering is a fundamental step. A detailed analysis of offset wells and geological risks would enhance the practicality and instructiveness of the engineering design. Technology innovation is of great importance in drilling the well safely and efficiently. Downhole mechanical measurements were analyzed in real time. The methodology and workflow were developed by utilizing downhole axial loading, torsional loading and pressure-while-drilling data in conjunction with surface drilling parameters, to assess downhole conditions. The new MWD (Measurement While Drilling) tool is taking survey while drilling, eliminating the need for static survey time, reducing downhole risks and saving rig time (Lowdon, 2021). 5 million capital expenditure saving was achieved by eliminating the need for titanium alloy drill pipe through comprehensive drilling string design and rig sizing evaluation. The well was drilled and cased successfully, creating several new records in China. These records include the longest production well, the longest 12.25in open hole section of 5124 meters, and the deepest 9-5/8in casing setting depth at 8125 meters. Sophisticated engineering, fit-for-purpose drilling technologies and customized solutions contributed to delivering the record ERD well in China. The successful delivery of the well demonstrated the overall strength and accuracy of the well plan developed, as well as the technologies and computer models incorporated. Real-time downhole mechanical measurements analysis played a crucial role in monitoring drilling operations and ensuring the well was drilled without any surprises. Advanced Rotary Steerable Systems (RSS) and MWD tools are essential for achieving directional control and drilling a smooth wellbore, which are critical for achieving low Friction Factor (FF) and ensuring successful casing installation. The paper will demonstrate how fit-for-purpose engineering solutions and technologies are delivering a well that is approaching the limit of feasibility. And comprehensive analysis of drilling mechanical measurements can significantly enhance the transparency of downhole conditions, narrow down hypotheses, and enable timely implementation of corresponding measures for complex downhole situations.