METHOD FOR DETERMINING A LEAKAGE PRESSURE Russian patent published in 2018 - IPC E21B47/117 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of drilling in the oil and gas industry in the construction of wells, in particular to methods for determining the prevention of complications in the form of absorption of drill mud and oil-well fluids. Method includes running a bit into the well on drill pipes to a cement plug, drilling out of the cement plug, drilling out of the casing shoe, drilling of the well, sealing of the annular space, pumping drill mud into pipes with pressure fixation, and plotting of a graph of the pressure rise versus the volume of pumped drill mud in the drill mud pipes. After drilling the casing shoe, drilling is carried out to a depth of 1–3 m, before pumping the drill mud into the pipes, the well is flushed out in the volume of the annular space of the well, and the fixed pressure during pumping is increased in steps with an interval of 0.2–0.5 MPa, in a range of 1–5 minutes, determination of a leakage pressure at a given depth is made by means of a start point of the disturbance of the linear dependence of the pressure rise in the well from the pumped volume, appliance of this leakage pressure determination method is performed each time the drill string assembly is raised to estimate the leakage pressure for a newly drilled interval.

EFFECT: technical result is to ensure the strength and reach the height of the cement lifting according to the project.

1 cl, 2 dwg