RU2211921C1 - Method of determination of pipe string length in round trip operations in well - Google Patents

Abstract

FIELD: oil and gas producing industry; applicable in determination of pipe string length. SUBSTANCE: method includes determination of pipe string length by summation of length of each pipe. Length of each pipe is determined by measuring its weight on hook of load-lifting plant and division of obtained weight by weight of running meter of this pipe. Value of running meter weight of each pipe is stored in controller memory. EFFECT: indirect determination of pipe string length with high accuracy without use of means for measuring length. 1 dwg

Description

 The invention relates to the oil and gas industry, in particular to methods for determining the length of the pipe string in the process of underground and workover.

 A known method of measuring the length of a pipe string during hoisting operations in the well, which consists in the fact that an information signal in the form of an angle of rotation is obtained from the winch drum, then through a kinematic transmission and reed switches this signal is converted into electrical pulses, which are fed to the block of meters generating information about the length of the column, and information about the length is transmitted only at the moments of automatic sensor activation (USSR Author's Certificate N 1550119, class E 21 B 47/04, publ. Bulletin 10, 1990).

 The disadvantages of this method are the low reliability, as well as the lack of accuracy in measuring the length of the pipe string.

 There is also a method of measuring the length of a pipe string during tripping in a well, described in a device for measuring the length of a pipe string (A.S. 1716113, class E 21 B 45/00, publ. 02.29.1992).

 The method implements the following operations: measuring the weight on the hook of the lifting installation, measuring the length of each pipe and calculating the length of the string of pipes lowered into the well by summing the lengths of each pipe.

 The disadvantages of this method are the significant cost of time and money for measuring the length of the pipe string, as well as insufficient accuracy.

 SUMMARY OF THE INVENTION The invention is directed to the creation of such a method, allowing with high accuracy to measure the length of the pipe string.

 The technical result representing the solution of this problem lies in the fact that, by measuring the weight of each pipe in the column, directly during tripping operations, and also without using special tools that measure the length of the pipe string, we increase the accuracy of measuring the length of the pipe string lowered into the well , and also reduce the cost of time and money.

 The specified technical result is achieved by the fact that during the round-trip operations in the well, including determining the length of the pipe string by adding the lengths of each pipe, the length of each pipe is determined by measuring its weight on the hook of the lifting device and dividing the weight obtained by the weight of the running meter of this pipe, This uses a controller, in the memory of which the weight values of a running meter of each pipe are placed in advance.

 The method is as follows.

 Before the descent of the pipe into the well, it is captured by the elevator and suspended on the hook of the elevator. Then measure the weight of this pipe. After that, the division of the value of the obtained weight by the weight of a running meter of this pipe, which is known in advance and placed in the memory of the microprocessor, is performed. The pipe is lowered into the well. After that, the next pipe is suspended on the hook and the process is repeated, and the obtained value of the division result in the latter case is summed up with the previous value and stored. The resulting amount, displayed in digital form, shows the length of the string of pipes lowered into the well.

 The drawing shows a block diagram of a device that implements the proposed method.

 The device consists of a load measuring unit 1, which is connected through an intrinsically safe unit 2 to the first input of the controller 3, the second input of the controller is connected to the output of the control unit 4, and the outputs of the controller 3 are connected to a memory unit 5 of the weight values of each pipe, with an indication unit 6, the power supply 7 provides the necessary supply voltages to all units of the device.

 The force measuring unit 1 consists of a force sensor and a transducer.

 It is mounted on a fixed flexible body of the elevator in such a way that the latter is refracted between the two extreme fixed stops and the pressure-bending device. The magnitude of the tension of the flexible organ determines the force acting on the strain gauge beam. Under the action of the measured force, the beam deformation causes a change in the resistance of the strain gages, which leads to an unbalance of the bridge and the appearance of an output signal proportional to the measured force. The converter is designed to receive a signal at the output of the block of the required size and shape for the operation of the device.

 Intrinsically safe unit 2 is designed to eliminate the danger of explosion, fire during operation of the device in places with explosive atmospheres. The block is made on resistors that limit the current in the power supply circuits of the sensors and the remote display unit to explosion-proof values. The values of the resistors are selected in accordance with GOST 22782.5. The block is limited on the circuit board circuit, which after installation is filled with a compound.

 Controller 3 is an independent system that contains a processor, auxiliary circuits, and data input-output devices.

Before performing tripping operations (STR), the device automatically resets the readings of all indicators of indication unit 6 to the program laid down in the controller 3. Thus, the influence of the weight of the moving block of the tackle system, the weight of the hook block, elevator, elastic deformation of the flexible organ, etc., is eliminated. on indicators when measuring the weight of pipes. When lowering the pipes, the operator grabs the pipe using an elevator suspended on the hook of the elevator, and then the driver lifts the pipe from the walkways. At this moment, the electrical signal from the output of block 1, proportional to the weight of the pipe, is fed through the intrinsically safe block 2 to the input of controller 3. Using the analog-to-digital converter of the controller, the incoming signal is converted into a digital code. Controller 3, according to the program embedded in its memory block, measures the value of the incoming signal proportional to the weight of one pipe and stores this value in memory block 5. For example, if the low-order price when using the 4-digit indicator of display unit 6 is 0.1 kg , with the weight of one pipe equal to 78.5 kg, the indicator will show a value of 078.5 kg. With a weight of 1 m running this pipe equal to 9.46 kg (taken from the directory and entered into the memory of the controller 3 using the buttons of the control unit 4), the length of this pipe will be equal
L = 78.5 / 9.46 = 8.298 m
After the descent of the pipe, the column is installed on the wedge captures and the weight on the hook drops to zero. The operator removes the elevator from the column and takes the next pipe from the bridges. The process is then repeated. Each subsequent value of the pipe length is added to the previous sum, and the result is placed in the memory unit 5. The resulting total number is equal to the length of the pipe string.

Claims (1)

 A method for determining the length of the pipe string during hoisting operations in the well, comprising determining the length of the pipe string by adding the lengths of each pipe, characterized in that the length of each pipe is determined by measuring its weight on the hook of the lifting device and dividing the weight by the weight per meter of the pipe, use a controller in the memory of which the weight values of a running meter of each pipe are placed in advance.