CN106014402B - A Filling Medium Measuring Instrument Used for Borehole Wall Deformation Detection - Google Patents

Abstract

A filling medium measuring instrument for wellbore deformation detection, the invention relates to the technical field of drilling wellbore deformation measurement, which solves the problem that the relative position of the wellbore deformation cannot be measured in the prior art, and its measuring device based on strain gauges Technical problems such as poor reliability, low precision and difficult installation. The present invention includes at least two independent sealed cavities, which jointly form a complete hollow cylinder, and the outer wall of the hollow cylinder is attached to the wall of the well; each independent sealed cavity is provided with a booster pump and a telescopic cylinder. The invention is used for well wall deformation measurement.

Description

A Filling Medium Measuring Instrument Used for Borehole Wall Deformation Detection

technical field

The invention relates to the technical field of drilling borehole wall deformation measurement, in particular to a filling medium measuring instrument for borehole wall deformation detection.

Background technique

For the current common deformation measuring instruments, the deformation of the object is generally measured by strain gauges (changes in resistivity, etc.), and better results can be achieved under normal circumstances. But for the special environment—the downhole environment of oil and gas, it will be impossible to measure it with conventional instruments. Its main disadvantages are as follows:

(1) The downhole environment of oil and gas wells is generally in an environment of high temperature and high pressure, and the performance of strain gauges is seriously affected by temperature. Therefore, the reliability of using strain gauges and related combinations to measure them is doubtful.

(2) Wellbore deformation (such as shrinkage) of oil and gas wells is generally a plane rather than a point or line, so it is difficult to achieve the expected effect with strain gauge measurement.

(3) The deformation of the object measured by the strain gauge is close to the surface of the object, and for the oil and gas wells of thousands of meters, the installation of the strain gauge has become a very real problem.

For well walls with complex environments and complex deformation characteristics (especially coal-rock well walls), to measure the entire dynamic process of well wall deformation, the accuracy of measuring with strain gauges is questionable.

Contents of the invention

In view of the above-mentioned prior art, the purpose of the present invention is to provide a filling medium measuring instrument for wellbore deformation detection, which solves the problem that the relative position of the wellbore deformation cannot be measured in the prior art, and its measuring device based on strain gauges is reliable. There are technical problems such as poor performance, low precision and difficult installation.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A filling medium measuring instrument for well wall deformation detection, comprising at least two independent sealed cavities, which together form a complete hollow cylinder, the outer wall of the hollow cylinder is attached to the well wall; each independent sealed cavity Both are provided with booster pumps and high-pressure telescopic cylinders respectively communicated with them.

In the above solution, at least three independent sealed cavities are included, and all the independent sealed cavities jointly form a complete hollow cylinder. The greater the number of independent sealed cavities, the greater the help in determining the relative position of the deformed well wall.

In the above solution, the at least three independent sealed cavities are respectively connected to each other through at least three cavity support isolation modules. Support the cavity; divide the cavity into 3 or more parts to facilitate the measurement of the deformation of each part; determine the deformation of the relevant orientation.

In the above solution, the independent sealed cavity includes two cavity support fan-shaped disks parallel to each other with equal inner and outer diameters; The inner diameter and outer diameter of the support sector disc match to form an arc cavity.

In the above solution, the arc-shaped support surface matching the outer diameter is made of high-strength flexible iron sheet.

In the above solution, each of the independent sealed cavities is also provided with a booster pump communicating with it, and the booster pump is provided with a barometer.

In the above scheme, the high-pressure telescopic cylinder is provided with a barometer.

Compared with prior art, the beneficial effect of the present invention:

(1) The relationship between wellbore deformation and time can be determined, and the minimum pressure to prevent wellbore deformation at different times can be determined, which provides a favorable reference for the subsequent more reasonable determination of the drilling fluid density window;

(2) This device can measure the maximum and minimum horizontal in-situ stress and the specific deformation of the borehole wall in the direction of the overlying formation pressure and their relationship with time;

(3) The chamber of the device can be filled with a variety of fluids, with a wide range of material choices, and the pressure value can be adjusted flexibly. It is applied to the measurement of wellbore deformation under various wellbore pressure conditions, so it has strong practicability;

(4) The device has simple structure, convenient operation, strong adaptability, high precision and reliable measurement results;

(5) The device can also support the drill pipe when necessary to prevent its disturbance from seriously affecting the drilling direction;

If the device is installed near the drill bit, when the well wall collapses and the drill bit is buried, the air outlet valve can be closed, the inflation valve can be opened, and the cavity can be inflated to enlarge the borehole, which is convenient for taking out the drill bit.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the present invention;

Fig. 2 is a schematic diagram of the specific implementation of the independent sealed cavity of the present invention.

Detailed ways

All features disclosed in this specification, or steps in all methods or processes disclosed, may be combined in any manner, except for mutually exclusive features and/or steps.

The present invention will be further described below in conjunction with accompanying drawing:

Example 1

Fig. 1 is a schematic diagram of a filling medium measuring instrument for wellbore deformation detection, and Fig. 2 is a 1/3 view. Its working principle is: when an elastic container filled with a certain volume (V ₀ ) of gas (liquid) communicates with another rigid movable container filled with gas (liquid), without any stress, the two containers will The pressure is the same. When the elastic container is subjected to a certain external force, it will deform, causing the gas (liquid) in the container to rise, and the gas (liquid) will flow in the direction of the rigid movable container until the pressure of the two containers is equal (that is, the principle of the connecting device) . Calculate the volume deformation and container pressure of the elastic container by the change of gas in the movable rigid container (ΔV) and the reading of the barometer (P).

Working process: place the device at the proper position behind the drill bit during the drilling process (can be adjusted as needed), lower it down the well together with the drill bit, then start the booster pump, and fill the device cavity with gas (during coalbed methane mining) It is best to fill with gas), and open the outlet valve of the gas outlet of the chamber at the same time. When the pressure gauge of the outlet cylinder reaches the bottom hole pressure P ₀ , close the inlet valve of the chamber and the booster pump. At this time, the volume of the outlet cylinder is V ₀ . With the advancement of drilling and the passage of time (t), when time t=i, the volume of the outlet cylinder is V _ti , and when the value displayed by the barometer is P _ti , it means that the volume deformation of the borehole wall is within the time 0-i is ΔV _ti =V _ti -V ₀ . ΔV _t(i+1) =V _ti+1 −V _i . By analogy, the volume deformation at time t can be calculated, and at the same time the minimum pressure value to prevent well wall deformation at this time can also be obtained.

The device is shown in Figure 1. The device consists of three air cavities 4, three cavity supporting isolation modules 3, three high-strength flexible elastic iron sheets, six gas inlets/outlets and two cavity supporting discs. Now take Figure 2 as a schematic diagram to make a specific description,

Surface AFGH, surface DEJL - 1/3 cavity support disc;

Body ABCDEF, body HIKLJG——cavity support isolation module 3;

Curved surface AHLD - high-strength flexible elastic iron sheet;

R, T - inlet and outlet holes;

Y——Boost pump 2 with barometer;

M——high-pressure telescopic cylinder 1 with barometer;

AHGF, HGJL, LJED, ADLH, EJGF, AFED form a 1/3 cavity;

Working principle: the inlet hole R is connected with the booster pump Y, and its function is that the booster pump Y injects a constant air pressure into the chamber to a predetermined air pressure value P ₀ , and at the same time opens the air outlet hole T, so that the barometer of the high-pressure telescopic cylinder M displays When the value is P ₀ , the booster pump Y, that is, the air inlet R, is closed. At this time, the air outlet T should always be in an open state. The change of the air pressure in the cavity is obtained by the change of the value of the air pressure gauge on the high-pressure telescopic tube M.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any changes or substitutions that can be easily imagined by those skilled in the art within the technical scope disclosed in the present invention, All should be covered within the protection scope of the present invention.

Claims (3)

1. A filling medium measuring instrument for borehole wall deformation detection, characterized in that it includes an elastic container, and the elastic container includes at least three independent sealed cavities, which together form a complete hollow cylinder, the outer wall of the hollow cylinder and the The well wall fits; Each independent sealed cavity is provided with a high-pressure telescopic cylinder and an air outlet connected thereto, and the high-pressure telescopic cylinder is provided with a barometer; The at least three independent sealed cavities are respectively connected to each other through at least three cavity support isolation modules; Each of the independent sealed cavities is also provided with a booster pump and an air inlet connected thereto, and the booster pump is provided with a barometer; The booster pump is connected to the air inlet, so that the constant air pressure charged by the booster pump into the cavity reaches a predetermined air pressure value, and the high-pressure telescopic cylinder is connected to the air outlet, and the air outlet and the air inlet are two non-overlapping holes; Calculate the volume deformation of the elastic container and the pressure of the container through the change of the gas volume in the high-pressure telescopic cylinder and the reading of the barometer; by calculating the volume deformation at time t, the minimum pressure value to prevent the deformation of the well wall at this time is obtained. 2. A filling medium measuring instrument for well wall deformation detection according to claim 1, characterized in that the independent sealed cavity comprises two cavities parallel to each other with equal inner and outer diameters Supporting the fan-shaped disc; it also includes two arc-shaped support curved surfaces, and the two arc-shaped support curved surfaces are respectively matched with the inner diameter and outer diameter of the cavity-supported fan-shaped disc to form an arc-shaped cavity. 3. A filling medium measuring instrument for well wall deformation detection according to claim 2, characterized in that the arc-shaped support curved surface matching the outer diameter is made of high-strength flexible iron sheet.