“The drilling fluid is performing better than we expected. As a result, the Black Sea project is a historic success.”
Fadil Duman, Drilling Manager
Park Place Energy
High-performance water-based drilling fluid reduces friction factor and optimizes ROP in Akcakoca Field, offshore Turkey
Location
Black Sea, Turkey, Asia, Europe, Offshore
Summary
The South Akcakoca Subbasin gas field in the Black Sea offshore Turkey is one of the region's largest natural gas projects. The HydraGlyde Optima™ flexible high-performance water-based drilling fluid system achieved a low friction factor of 0.15 and completed a smooth drilling and casing landing.
Objective
Park Place Energy, a subsidiary of Trillion Energy International, expanded horizontal drilling in the South Akcakoca Subbasin gas field in the Black Sea offshore Turkey. The operator planned a reentry of a mature well at 308 ft [94 m] water depth in the shale and sandstone formation. The plan was to complete an 8½-in section.
A high 0.35 friction factor occurred in earlier vertical wells in the formation. If the friction factor goes higher, drilling must stop immediately. Oil-based drilling fluid would lower the friction factor, but oil-based fluid is not a viable solution due to the Black Sea's “zero-drop” policy and the high cost of drilling fluids, waste management, and storage that come with it.
Solution
The operator went with the SLB-recommended HydraGlyde Optima flexible high-performance water-based drilling fluid system. The HydraGlyde Optima system delivers comparable results to oil-based mud (OBM) while maintaining the qualities of water-based mud (WBM). The system also delivers a high-quality filtercake and a low-tortuosity wellbore that minimizes the risks of differential sticking
After the operator completed the milling operation, the HydraGlyde Optima system was implemented for drilling the sharp-angle incline section of the horizontal. The HydraGlyde Optima system includes HydraSpeed II™ anticrete lubricant, HydraHib™ shale inhibitor for its high-level shale inhibition, and HydraCap™ encapsulating additive for its exceptional clay removal capacity.
Results
SLB created the drilling fluids plan for HydraGlyde Optima system product concentrations and wellbore strengthening system to achieve the customer's targets. The engineers further optimized the HydraGlyde Optima system fluid concentrations on the rig site for the horizontal section that started at 574 ft [175 m] and progressed up to a 74° inclination. The inclination decreased
to 7,053 ft [2,150 m] and reached 25° at 9,186 ft [2,800 m]
The HydraGlyde Optima system achieved a low friction factor of 0.15 and enabled a smooth drilling and casing landing. As a result, the Park Place drilling managers removed all the other synthetic-fluid alternatives and plan to continue drilling with the HydraGlyde Optima system on this project.
The HydraGlyde Optima system achieved a low friction factor of 0.15 and enabled a smooth drilling and casing landing.
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