A High Molecular Polymer LCM to Cure Severe Losses While Drilling Shallow Aquifers in UAE

Abstract

Today, well durations are relatively longer due to several factors. Some of these include but not limited to intermediate section down hole losses. Therefore, there is an opportunity to explore possible ways to reduce well duration and cost while meeting all business objectives with 100% HSE. Dammam, U.E.R, and Simsima are karsts-prone carbonate aquifers widely developed across UAE. As formation pressures are depleted, severe to total losses is increasingly occurred during drilling through these shallow aquifers. Conventional loss curing agents are often failed, especially in Simsima, because of their inability to set in such complex and large fractures and caverns. ZND gel is a water-soluble high molecular polymer, which will automatically set and seal the space after being pumped into loss channels. As hardly be diluted by any formation fluid, a gel slug is formed to isolate drilling fluids and consolidate agent from being washed away into loss zones. In this study, we present a composite solution of ZND gel and Cement applied in onshore Abu Dhabi, which effectively mitigated the total losses encountered in Simsima.