Sustainable Practices for ERD Cementing: Success Story from Arabic Gulf

Abstract Wellbore integrity is particularly complex during extended reach drilling (ERD) operations, and the curve section is one of the most complicated intervals. In the Arabic Gulf, reliable cement barriers in long horizontal sections are frequently compromised by weak formations, pipe standoff limitations, inadequate equivalent circulating density (ECD) management, and mud displacement issues. The application of advanced engineering practices and state-of-the-art cementing techniques under these conditions are highlighted and supported by discussion of successful case studies. Robust engineering best practices and superior field execution were essential to meet operator requirements. Custom fluid designs were meticulously tailored and monitored to ensure optimal slurry and spacer performance. This included cement fluid-loss management, compressive strength development, enabling the spacer-to-bridge thief zones, exceptional bonding between the cement and wellbore, ECD control, and precise slurry placement within designated depths. The selection of casing hardware was also vital; the combination of centralizers improved standoff values, optimized torque-and-drag forces, and helped ensure the planned casing point was achieved. A specialized shoe-track arrangement was introduced to mitigate undesired cement consistency during drill out. A campaign of seven wells were executed and deemed successful by the operator. Comprehensive evaluation through positive and negative pressure tests and cement bond logs (CBLs) demonstrated excellent cement coverage and bonding. Preapplication verification testing of all slurries with mixing fluid samples and location blends confirmed their readiness for flawless execution, with slurry behavior consistent with initial tests. Early development of set cement compressive strength and low slurry fluid loss were fundamental to minimize shoe-track contamination and achieve the necessary top of cement (TOC). Spacer and slurry designs and volume met fluid dynamics and mud removal requirements, which allowed ECD control and effective cement placement. Pressure values during pumping closely aligned with simulation results, which facilitated well-controlled execution and predictable job success. The appropriate selection of casing hardware enabled the crew to reach the casing point in each well and ensure sufficient standoff for optimal cement coverage. The operator's confidence in the design led to its use even when the previous casing was set beforehand, which allowed successful cementing of challenging zones traditionally left as pay zones. The tailored solutions implemented in these ERD wells can help enhance best practices to achieve outstanding cement bonding and shoe integrity while cementing long horizontal pipe in weak formations with narrow ECDs.