RU2167287C2 - Method of operating wells research - Google Patents

Abstract

FIELD: oil producing industry; applicable in geophysical and hydrodynamic researches of operating wells. SUBSTANCE: method includes running of geophysical device into well before lowering of tubing for obtaining diagram of location of casing string collars. Diagram is tied to geological section of said well with the help of gamma-ray log. Run into well on scraper wire is self-contained downhole instrument including device for measurement of physical parameters and locator of collars. Physical parameters are registered at constant speed of motion of self-contained downhole instrument along wellbore and simultaneously depth of downhole instrument location is registered by surface measurement device. After withdrawal of self-contained downhole instrument from well, results registered by self-contained downhole instrument, surface depth measurement device and data obtained earlier by geophysical device are subjected to combined processing. EFFECT: simplified technological process of research; ecological cleanness.

Description

 The invention relates to the oil industry and can be used in geophysical and hydrodynamic studies of existing wells.

 There is a method of researching existing wells by lowering a stand-alone device into the well and recording readings on a diagram form of a carriage installed in the device itself and set in motion by means of clock mechanisms and devices (1). Moreover, to bind the readings recorded on the form to the section of the well, stop for fixed periods of time at certain depths of immersion of the device in the well.

 The main disadvantages of this method are the limited number of measurement points, the low reliability of the results due to the lack of the possibility of accurate reference to the geological section of the well and the impossibility of multiple repeated measurements at the same points.

 A known method of constructing curves of changes in physical parameters along the barrel of existing wells by lowering into the well a remote device on an armored wireline cable (2).

 A remote device is lowered into the well, connected via a logging cable to the ground equipment, which serves as the power unit of the device and the recorder of the physical parameters measured by it. Typically, the recorder diagram is driven by devices that have kinematic or electrical communication with a depth gauge for immersing the device in the well.

 To study existing wells, armored single-core or three-core cables are used that are inserted into the well through an stuffing box mounted on a lubricator that serves as a lock chamber between the buffer valve of the well and the stuffing box when the tool is lowered into the well.

 This method allows you to build a continuous curve of changes in physical parameters along the wellbore, that is, to obtain an almost unlimited number of measured points with high accuracy and reliability of the results.

 The disadvantages of this method are the difficulty of lowering the downhole tool on the cable into the wells with high wellhead pressure due to the large value of the buoyancy force on the cable and the inability to completely seal the wellhead using the stuffing box for the logging cable (armored) during the research period. The latter leads to environmental pollution associated petroleum gas, oil and water containing many harmful substances.

 For launching downhole tools into wells with a high wellhead pressure, special loads are suspended from the device, the length of which reaches several meters. To lock such a garland, multi-section lubricators are used - masts of high height, which are mounted on the wellhead before conducting research. Such a research technology is not only time-consuming and unsafe, but also environmentally harmful, because due to the lack of the possibility of pulling up the stuffing box located high above the mast, the amount of liquids and gases leaking into the environment will increase as the sealing element wears.

 To run downhole tools into injection wells with a high wellhead pressure until a certain weight of the cable with the device is located in the tubing cavity, the well is put on a self-discharge through the annulus. According to modern requirements for a clean environment, this is completely unacceptable.

 As a prototype, a method has been adopted for researching existing wells, which consists in launching an autonomous downhole tool into a well on a scraper wire, recording physical parameters at a constant speed of the device along the wellbore, and simultaneously recording the depth of an autonomous downhole tool in the well with a ground gauge and removing it from wells (3).

 The technical result of the invention is the simplification of technological processes and ensuring environmental cleanliness when conducting research on existing wells.

 It is achieved by the fact that before the descent of the tubing, the location diagram of the couplings of the casing string of the pipes and the gamma-ray log are taken, with the help of which the location diagram of the couplings is connected to the geological section of the well, an autonomous downhole tool with the coupling locator is lowered into the well with at a constant speed of the device’s movement along the wellbore, the values of physical parameters are recorded and at the same time, the surface meter records the depth of the autonomous downhole tool in the well no. After extracting the stand-alone downhole tool, the joint processing of the results recorded by the stand-alone downhole tool, a ground depth meter and previously obtained by a geophysical device is carried out.

 In accordance with the proposed method for researching existing wells during construction of a well or during the repair of underground technological equipment before lowering the tubing, a geophysical instrument is lowered into the well using a logging cable consisting, for example, of a gamma radiation intensity meter and coupler locator. At the same time, the gamma-ray log and the location diagram of the pipe casing couplings are taken. In this way, a clutch location diagram is attached to the geological section of the well using a gamma-ray log.

 When constructing a curve of a change in a physical parameter (for example, temperature) along an active well bore (for example, gushing), an autonomous borehole device consisting of a physical parameter meter and coupler locator is lowered into it on a scraper wire. The descent depth of an autonomous downhole tool is monitored and recorded at the wellhead using a surface depth meter that measures, for example, the length of the scraper wire lowered into the well. In the depth intervals where the curve of the physical parameter changes is built, the movement of an autonomous downhole tool along the wellbore is performed at a constant speed, the value of which is measured and stored at the mouth. The registration of the readings of the physical parameter meter and the locator of the couplings in an autonomous downhole tool and the readings of the ground depth meter is carried out at certain intervals simultaneously and synchronously in their memory.

 The simultaneous recording of the readings of an autonomous downhole tool and a ground-based depth gauge is ensured by the fact that both of them are equipped with synchronously working electronic timers, which serve both as timers from the start of a well survey and as adjusters of the measurement recording mode. At the same time, registrars (for example, made in the form of electronic hard memory) of an autonomous downhole tool and a ground depth meter simultaneously with the registration of the readings of a physical parameter meter, a coupler locator and a ground depth meter, respectively, record the readings of time-measuring devices.

 After extracting the stand-alone downhole tool from the well, joint processing of the results recorded by the stand-alone downhole tool, ground-based depth gauge and previously obtained (before the launch of the tubing) by the geophysical device is carried out.

 The advantage of the proposed method is that it simplifies the technological processes and ensures environmental cleanliness when conducting research on existing wells.

Literature:
1. Petrov A. I. Depth devices for well research, M., Nedra, 1988, p. 110-115.

 2. Gabdullin T.G. Operational study of wells, M., Nedra, 1981, p. 8-14.

 3. Gabdullin T.G. Operational study of wells, M., Nedra, 1981, p. 15, 31, 178-179n

Claims (1)

 The method of researching existing wells, which consists in launching an autonomous downhole tool into a well on a scraper wire, recording physical parameters at a constant speed of the device along the wellbore and simultaneously recording a depth gauge for finding an autonomous downhole tool in the well and removing it from the well, characterized in that before the descent of the tubing by means of a geophysical instrument lowered into the well, get a diagram of the location of the casing couplings to pipe columns and tie it to the geological section of this well using a gamma-ray log, and after removing the stand-alone downhole tool from the well, the results recorded by the stand-alone downhole tool, ground-based depth gauge and previously obtained by the geophysical instrument are combined.