Popis: |
The majority of promising oil and gas fields in Russia are located far north in remote, sparsely populated areas lacking infrastructure. The Srednebotuobinsky oil and gas field is one such example with stringent well construction, planning, and design requirements, particularly related to the selection of drilling fluids. Drilling fluid selection is essential to help: achieve successful well construction, ensure wellbore stability, carry out and suspend cuttings, establish hydrodynamic equilibrium in the "wellbore-reservoir" system, prevent the ingress of gas, oil, and water, plug permeable formations, and preserve reservoir properties of the productive formation. The main criteria for selecting a drilling fluid includes compatibility with the geological section, meeting design parameters, and environmental compliance/personnel safety. Projects in the far north are subject to additional criteria related to logistics, such as the ability to transport necessary materials by truck, the availability of roadways limited to the winter months, and abnormally low ambient temperatures. This paper presents optimization results for a drilling fluid selected for penetration into a productive formation with an abnormally low reservoir pressure in the Srednebotuobinsky field. Also included are drilling fluid formulations, laboratory testing results, hydraulic calculations, and the technical and economic benefits of using a novel mud, which is a direct emulsion of mineral oil in water with biodegradable polymers. |