SU1609991A1 - Method of determining upper boundary of pipe string seizure - Google Patents

Abstract

This invention relates to field geophysics. The goal is to improve the accuracy of determining the upper limit of sticking of a pipe string. The measurement of the distance between the coupling joints is carried out with the help of two locators fixed on the rod to the base distance. The difference in length between the sleeve joints and the base distance to the tensile force is recorded. A tensile force is applied to the column. The difference in length between the base distance and the coupling joints is recorded again. By the presence or absence of the increment of the difference in lengths, the upper boundary of the sticking of the pipe string is judged. 1 il.

Description

The invention relates to field geophysics and is intended to determine the upper limit of sticking of a pipe string and to eliminate accidents in wells.

The purpose of the invention is to improve the accuracy of determining the upper boundary of the sticking of a pipe string.

The drawing shows a block diagram of the device for implementing the proposed method

The device for determining the upper limit of sticking contains the first and second locators 1 and 2 couplings, rod 3 of fastening locators 1 and 2, shaper locator signal 4 of couplings, sensor 5 depth, control unit 6, recorder 7, counter 8 couplings, calculator 9, and a storage unit 10,

The method is carried out as follows.

Locators 1 and 2 are mounted on rod 3 at the base distance. The distance between the coupling joints is measured using locators 1 and 2. The difference of the distance between the coupling joints and the base joint is recorded. A tensile force is applied to the column. Re-fix the difference between the base distance and the distance between the coupling joints, by the presence or absence of an increment of which is judged on the sticking point.

The device works as follows.

The locators 1 and 2 of the couplings are lowered into the intended sticking interval. Locators 1 and 2 of the couplings are rigidly connected at a fixed distance by means of a rod 3 and work for one input of the device. After the locators 1 and 2 of the clutches have reached the interval of the intended sticking with the aid of the control unit 6, the device is reset.

ABOUT

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With a negative impulse from the control unit 6, the counter of the 8 sleeves is zeroed, with the logical unit from the control unit 6, the calculator 9 is switched to the tube length measurement mode, and the storage unit 10 to the write mode.

When raising the locators 1 and 2 of the couplings, the depth sensor 5 converts the movement of the locators into a sequence of pulses proportional to the length, with each pulse of the depth sensor 5 corresponds to moving the locators 1 and 2 of the couplings, for example, by 1 mm, and the shaper 4 of the signals of the locator couplings forms a single impulse when locators 1 and 2 pass by the coupling connection,

In this case, the pulse sequence enters the calculator 9. When a pulse arrives from the generator 4, the counter 8 clutches are transferred to the next state, giving the command to the calculator 9 to transfer the measured value to the storage unit 10. Then the measurement of the next value begins.

This process is repeated until the end of the measurement in the range of intended sticking. In the storage unit 10, the length difference between the couplings and between the locators in the binary code is stored in each address.

Consider two cases.

1. The distance between locators 1 and 2 is less than the distance between the couplings by the value of A, then the amount of displacement in length between arrivals of pulses from the second, then from the first locators gives the difference in length between the couplings and between the locators and is stored in its address,

and the value between the pulses coming from the first, then from the second locators, gives the value of the distance between, the locators,

2. The distance between locators 1 and 2 is longer than the distance between the couplings by the value of Л, then the amount of misalignment in the length between the arrival of pulses from the second, then from the first locators gives the difference between the locators and the distance between each first and third couplings , and the value between the pulses from the first, then the second locators gives the difference of the distances between the locators, and between the first and second couplings. These values are written to the storage unit 10 in binary code.

When the upper limit of the measurement interval is reached, the coupling locators 1 and 2 are lowered to the depth corresponding to the beginning of the first measurement, then the maximum allowable tensile load is created and the second measurement is made with this load on the pipe string. At the same time, before starting the measurement with the aid of, the control unit 6 resets the clutch counter 8, the storage unit 10 is transferred to the read mode, the calculator 9 is switched to the calculation mode of the increment in the length of the distance difference between the couplings and between the locators 1 and 2 due to nor the tensile force and transfer of the accumulated sum of the increment values to the recorder 7.

With the arrival of the pulse of the imaging device 4, information is entered from the next cell of the storage unit 10 into the calculator 9. Pulses from the 5 g sensor;} The drums arrive at the input of the calculator 9. Before the next pulse of the imaging device 4 arrives from the code value corresponding to the distance difference between the couplings and using locators to deform the pipe, calculator 9 subtracts the corresponding value at the maximum tensile force, forming an increment value.

When the next pulse of the former 4 arrives, the envelope 9 generates a length increment and the accumulating sum of length increments is transmitted to the recorder 7 and the clutch counter 8 simultaneously switches, and the information from the next cell of the storage unit 10 is entered into the calculator 9. The measurement cycle repeats until completion measurements. By the presence of the absence of increments, it is judged on the place of sticking.

The application of the method allows to reduce the effect of uneven movement of the downhole tool with a uniform cable movement at the wellhead on the measurement results.

Claims (1)

Invention Formula The method for determining the upper limit of sticking of a pipe string, including sequential measurement of the distances between couples of coupling joints before and during the action of the tensile load and determining the increments of distances, by the presence of which determine the upper limit of sticking, characterized in that sticking measurements, measurements are made by two coupling locators separated by a base distance, and the distance increment is defined as the difference between the base distance and the span m between couples coupling connections.