First Application of Biogenic Fibres in a Reservoir Drilling Fluid to Enable Safe Drilling and Data Acquisition Across a Depleted, Highly Laminated, Carbonate Reservoir With Heterogenous Characteristics

Abstract

Abstract Drilling and completion operations across mature reservoirs are challenging due to high overbalance pressure and become even more so when extended static time is required to satisfy data acquisition requirements. A major Operator in the UAE typically drills challenging 6-inch horizontal drains which cross several heterogenous layers with pore pressure requirements varying from equivalent mud weights of 14.5 ppg to as low as 6.0 ppg across the exposed reservoirs. With increasing data collection requirements there was a high incidence of stuck pipe events during Modular Dynamics Tester (MDT) operations, which led to significant Non-Productive Time (NPT) while attempting to release the stuck pipe. As a short-term mitigation measure additional work was done optimizing the bridging package along with increased sacrificial treatments and monitoring to ensure compliance with the required bridging scheme. In parallel, a longer-term strategy was initiated to examine alternative fluid systems or products to mitigate against stuck pipe as Well-As aids for releasing stuck pipe. This paper presents the methodology for the design and field validation of an engineered Reservoir Drilling Fluid (RDF) solution with a thin cohesive filter cake and minimal pore pressure transmission characteristics to achieve well objectives.