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Directional casing while drilling (DCWD) utilizing a rotary steerable system or a steerable positive displacement motor is a recent enabling technological application of proven casing while drilling. DCWD has been successfully applied in wells in the North Sea and Middle East using both rotary steerable systems and PDMs, proving up its operational reliability. The technology has most recently been utilized in a project from a producing platform in the Asia Pacific region. While this DCWD application increases the challenges of directional drilling, the project was completed successfully in terms of increasing ROP and lowering the time and cost to drill the top hole section of the well.Top hole directional drilling of wells in high density locations such as multi-well producing platforms require carefully planned, detailed procedures and reliable techniques to result in a safe and efficiently drilled wellbore. The procedure, in addition to directional capabilities, requires that the well meet the demands of anti-collision concerns within the torque and hydraulic operating parameters of the formation. The drive for continuous improvements led the field operator to choose DCWD technology to deliver step changes in drilling performance while meeting the company's strict operational and safety directives.The successful effort was a carefully planned and implemented operation that required the close cooperation of the operator, directional drilling company and drilling contractor during the entire procedure. This close interaction between all parties led to three world records and the world's first application of another enabling technology, including:• World's deepest 13 3/8" DCWD job;• World's highest angle directional well with 13 3/8" DCWD;• World's fastest rate of penetration for a 13 3/8" DCWD;• World's first application of Gyro MWD with DCWD. OTC 20880As a result of the success of DCWD in top hole formations from a producing platform, the operator considers DCWD as a primary enabling technology in its continued efforts for drilling efficiency and is deploying the DCWD technology in another of its projects in East Malaysia.PETRONAS collabarate with service provider to make this project success and beneficial to oil and gas industries. The objectives were to reduce the drilling cost and NPT combating losses.The following paper discusses the challenges, planning, implementation, economics and operational results and lessons learned from a two-well DCWD batch drilling program from a producing platform offshore Malaysia.

Directional casing while drilling (DCWD) utilizing a rotary steerable system or a steerable positive displacement motor is a recent enabling technological application of proven casing while drilling. DCWD has been successfully applied in wells in the North Sea and Middle East using both rotary steerable systems and PDMs, proving up its operational reliability. The technology has most recently been utilized in a project from a producing platform in the Asia Pacific region. While this DCWD application increases the challenges of directional drilling, the project was completed successfully in terms of increasing ROP and lowering the time and cost to drill the top hole section of the well. Top hole directional drilling of wells in high density locations such as multi-well producing platforms require carefully planned, detailed procedures and reliable techniques to result in a safe and efficiently drilled wellbore. The procedure, in addition to directional capabilities, requires that the well meet the demands of anti-collision concerns within the torque and hydraulic operating parameters of the formation. The drive for continuous improvements led the field operator to choose DCWD technology to deliver step changes in drilling performance while meeting the company's strict operational and safety directives. The successful effort was a carefully planned and implemented operation that required the close cooperation of the operator, directional drilling company and drilling contractor during the entire procedure. This close interaction between all parties led to three world records and the world's first application of another enabling technology, including:World's deepest 13 3/8?? DCWD job;World's highest angle directional well with 13 3/8?? DCWD;World's fastest rate of penetration for a 13 3/8?? DCWD;World's first application of Gyro MWD with DCWD.

Two optimized polymer/borate/salt (PBS) fluid loss systems were recently implemented in two different ADNOC Sole Risk (ASR) wells while drilling different troublesome formations in the Arabian Gulf which are prone to losses. The first well (Well A) was drilled through the fractured Upper Khuff Formation, and the second well (Well B) through porous Arabs and fractured Diyab/Jubaila groups. The application of the PBS systems enabled the rigs to regain circulation and successfully drill to the total planned depth with less non-productive time attributed to curing losses. The wells involved several different key objectives; however, zonal isolation and logging were critical to both. In addition, the ability to control losses, even at an acceptable rate for one of the wells, allowed the team to proceed with the critical logging program. If not mitigated, losses could have resulted in a well-control situation. Controlling the losses on Well A allowed the first unimpeded logging suite, including high quality imaging, pressure sampling and avoidance of a liner run. After logging the section, drilling was resumed to the planned section total depth, and the liner was run and cemented successfully. The application of the PBS system in Well B allowed multiple troublesome formations (Arabs/Diyab/Jubaila/Gulailah/Sudair) to be drilled as one interval and successful isolation of these zones. The losses were completely cured after applying this system in the correct zone. The total planned depth was attained and the casing landed and cemented. The solution for these loss-circulation challenges when drilling was the development of a faster, as well as flexible, setting and crosslinking PBS system that could effectively bridge and/or adhere to the formation rock. The optimization also included extending thermal stability of the set plug to maintain a workable loss rate at the anticipated elevated temperatures and simulations to ensure the system would agglomerate and adhere to the limestone/dolomite rocks. Pre-planning started nine months prior to drilling these wells. The predicted challenges ranged from managing losses to developing contingencies for total loss of circulation through the above-mentioned formations. Contingency systems were devised using a decision tree and rig instructions were prepared for every wellbore/scenario. The planning process included determination of a pumpable volume that would facilitate spotting this fluid loss system only once. This paper outlines the successes achieved in curing loss circulation in the 8⅜-inch section of Well A within the Khuff formation and the 12¼-inch section of Well B within the Diyab group formation. These were drilled in ASR Arabian Gulf region as shown in Fig. 1. Figure 1Location of the ASR wells in the Arabian Gulf.

Two significant development projects were being planned for brownfields in southeast Asia with a total of seven platforms and 230 wellbores in place. Previous drilling campaigns were conducted from 10 to 30 years ago. Hence, existing data were of variable quality and reliability. During the design process for both fields, it was determined that there were large discrepancies and irregularities between well positioning databases. This not only complicated the anticollision situation of drilling in the congested fields but could also influence the reservoir model accuracy for determining the development target. The anticollision risks based on the existing data meant that well plans had to be "over engineered" to avoid the perceived risks while also requiring offset wells to be shut in during drilling operations. Thus, both drilling efficiency and production were affected because of the well positioning uncertainties. A comprehensive survey management process was embarked upon by both the operator and service company to ensure that the survey databases being used by the drilling and subsurface teams were consistent and free from gross errors. This included the review of all existing survey reports, sources of platform positions, etc. to identify anomalies or gross errors. This was the first such project conducted by the operator. This paper discusses the complete survey management validation process and also highlights its effect in allowing the safe and efficient well planning of the drilling campaigns while providing the subsurface team an accurate well positioning database to allow accurate target selection.