METHOD FOR CONSTRUCTION OF WELLS ON THE TERRIGENOUS DEVONIAN DEPOSITS OF THE ROMASHKINO OIL FIELD Russian patent published in 2021 - IPC E21B7/20 E21B43/10 E21B33/14 

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry and, in particular, to the construction of oil wells in difficult conditions of collapse of unstable rocks. The technical result is to reduce the time spent by the Kynov mudstones in the uncased state up to 48 hours due to geophysical surveys in 2 stages, elimination of complications during the construction of Devonian wells due to the exclusion of work on the development of the wellbore before running the production string. According to the method, a well is being constructed on the terrigenous Devonian deposits of the Romashkinskoye oil field. For this, a well is drilled, geophysical surveys, production casing running and its cementing are carried out. At the same time, drilling is stopped at an elevation of 10-50 meters above the top of the Kynovsky horizon. The well is flushed with drilling fluid. Then the first stage of geophysical surveys is carried out along the drilled wellbore. Then a well is drilled to the target bottom, exposing the productive Kynovsky and Pashi horizons. Then the second stage of geophysical surveys is carried out only in the productive part of the formation. After that, without preliminary reaming of the wellbore, a production string with a reaming shoe is lowered and cemented. After the cement has hardened, the well development is started.

EFFECT: wellbore development work time decreased, complications eliminated.

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