Zero-Time Definitive Dynamic Survey Reduced the Risk of Differential Sticking and Optimized the Drilling Efficiency in Offshore Project in Turkmenistan
Authors: Abdulrahman Abdulrazzaq , Fahmy Fadi , Dairova Bakytgul , Babanyazov Parahat , Mollaniyazov Vepa 
Published: May 2024

The objective of this paper is to share experience of implementing the rotating six-axis measurements-while-drilling to reduce the risks associated with differential sticking while drilling depleted reservoirs in the Cheleken Contract Area, Caspian Sea, Turkmenistan. Measurement-while-drilling (MWD) surveying procedure worldwide requires to completely cease drilling operations and maintain the drill string stationary for certain amount of time, and it will be needed to be repeated every 90 feet or even more frequent depending on the well profile and survey requirements. With a stationary drillstring and overbalance across permeable formation, the differential sticking risk increases significantly and may cause disruption of the well delivery schedule and incur additional costs related to fishing operations, LIH incidents and drilling another sidetrack to reach target reservoirs. The alternative methods of reducing the stationary time spend for survey were considered with adopting the recent change to ability to take the survey while rotating without compromising the quality. The Oil and gas industry has experienced multiple evolutions of MWD surveys, but none of them lead to achieving the six-axis surveying in dynamic conditions with at least the same accuracy as static surveys. Realizing the true potentials of getting the survey data in rotating mode helped to optimize the drilling operation and minimize the risk associated with stationary survey time. Those Definitive Dynamic Surveys (DDS) can be taken at the pre-set time intervals while drilling (rotating, without the need to stay stationary or recycle the pumps).

Dragon Oil together with a major directional service provider has implemented the DDS to two operating fields in Caspian Sea. The technology delivered definitive surveys while on bottom drilling with full parameters and complete data quality control. The several operational runs delivered where more than 100 DDS survey obtained with zero stationary time through depleted formation. The technology helped to save not only time that usually spend for survey operation itself, but also reducing the time that usually spend for stuck pipe release operation that historically often led to BHA LIH and borehole re-drill in the area. There were zero LIH or stuck pipe incidents due to differential sticking on the project from the time the technology implemented.

The proposed paper will review the recent results of implementing the DDS technology while drilling in the Caspian region and share the best practices for planning and executing a similar job. To validate rotating six-axis measurements, the authors will present the survey comparison with conventional static survey in the field test run, as well as further work recommendations to transform the well construction process with great impact in drilling efficiency, as well as minimizing the stuck pipe risk and wellbore uncertainty.