SU1275090A1 - Method of determining rate of propagation of shock wave in boreholes - Google Patents

Abstract

The invention relates to the drilling of oil and gas wells and makes it possible to simplify the process of determining the velocity of propagation of a shock wave in drilling wells. When the drilling tool (BI) is raised, a zone of reduced pressure is formed under the bit. The underpressure wave propagates from the wellhead to the wellhead through the drilling fluid. When the wave reaches the wellhead, a decrease in the pressure and flow rate of the BR exiting the well is recorded. The time is measured from the beginning of the rise of BI to the time of registration of the pressure drop on the stand ti and until the decrease in the discharge of the BR at the mouth ta. The velocity of propagation of the shock wave in the drill pipe Vf) T and in the annulus space is then determined. according to the formulas WT and lit and Uz.p. H / ti, where H is the depth of the bit at the time of the § implementation of the measurement. The measurement is carried out in the process of drilling at the separation of the BI (L from the bottom. It takes place every 15 minutes and is a necessary operation when drilling deep wells.

Description

N5 recounted

The invention relates to the drilling of oil and gas wells and can be used in the creation of systems and devices for determining the velocity of propagation of shock waves along a well in the well.

The purpose of the invention is to simplify the process of determining the velocity of propagation of a shock wave in drilling wells.

The method is carried out as follows.

When the drilling tool is raised below the bit, a zone of reduced pressure is formed. The underpressure wave propagates from the wellhead to the wellhead through the drilling fluid that fills the drill pipe and annulus. Before the wellhead, this pressure wave is detected by wellhead equipment: in the drill pipe by means of a pressure sensor that detects a drop in pressure, and in the annulus by a flow sensor to reduce the flow rate of the drilling fluid. Thus, measuring the time from the beginning of lifting a drilling tool to the moment the gauge pressure is measured at the stand (ti) H and the reduction of drilling fluid flow at the wellhead (to) makes it possible to determine the velocity of propagation of the shock wave in the two drill pipes and annular annulus according to the formulas

Ub.t and;

H

UZ.P.

tT t |

where H is the depth of the bit at the time of the measurement. The advantage of the proposed method lies in the fact that a shock wave is created at the bottom of a well by means of lifting a drilling tool, which does not require any special devices or additional unproductive operations (measurement is carried out during the drilling process when the tool is detached from the hole, which occurs every 15 mine is a mandatory operation when drilling deep wells.

Claims (1)

Invention Formula A method for determining the velocity of propagation of a shock wave from boreholes based on measuring the travel time of a wave, characterized in that, in order to simplify the process of determining the velocity of propagation of a shock wave, the latter is created by lifting the drilling tool. tool until pressure drops by ke; and until the reduction of the mud flow rate at the outlet from the mouth of the t2 well, and the scattering rate of the shock wave in the drill pipe and in the annulus is determined by the formulas v .., H ti | de N - the depth of the bit in the moment of the moment of measurement.