RU2057924C1 - Gyroinclinometer complex - Google Patents

Abstract

FIELD: hole drilling. SUBSTANCE: gyroinclinometer complex incorporated ground equipment and down-hole logging instrument carrying three-degree gyroscope with outer axis directed along longitudinal axis of instrument. Apart from these complex is supplemented with ground setting system. Setting system is composed of units of computer, constants input analyzer, key element and unit of sensitive elements. For period of setting unit of sensitive elements is unambiguously mechanically joined to case of down-hole logging instrument. When down-hole instrument is immobile computer unit determines zenith and apsidal angles and azimuth of inclination plane of unit of sensitive elements by information from sensitive elements - two-component accelerometer and gyroscopic transducer of angular velocity and consequently of down-hole logging instrument. Analyzer unit is controlled by key element which breaks communication channel of computer and ground equipment to block information generation into ground equipment in case of occasional movements of down-hole logging instrument. EFFECT: improved precision in determination of spatial position of axes of boreholes. 1 dwg

Description

 The invention relates to systems and complexes for determining the spatial position of the axis of a borehole, in particular to gyroscopic inclinometers (gyroinclinometers).

 The inclinometer complex with a drive communication channel consists of ground equipment and a downhole tool connected by a logging cable. In downhole gyroclinometer instruments, gyroscopic instruments can be used to determine the position of the geographic meridian plane: gyrocompasses [1] and angular velocity sensors measuring the components of the Earth’s angular velocity [2, 3] The gyroclinometers mentioned have the disadvantage that they can only be measured with with a stationary downhole tool (with periodic stops of the latter when it moves along the axis of the well). This circumstance significantly increases the time of the well inclinometry process.

 The gyroinclinometer circuit selected as a prototype is free from such a drawback [4] The downhole device of this gyroinclinometer has a three-stage gyroscope, the external axis of which is directed along the longitudinal axis of the device, and the main axis keeps its position in space unchanged both during movement and when the borehole stops device. This position, which is unchanged relative to the meridian plane, is used as a reference when conducting measurements in the well. The signal of the angle sensor associated with the external axis of the gyroscope enters the surface, where it is used in the ground equipment, which is part of the complex, to determine the azimuth of the inclination plane.

 The most significant drawback of this gyroclinometer is the length and complexity of the process of exhibiting (orienting) the gyro on the Earth’s surface relative to the reference coordinate system. The essence of the exhibition is that the downhole tool connected to ground equipment and operating in the normal mode deviates from the vertical position, i.e., is brought into an artificially created inclination plane. In this case, information is removed from the sensitive elements of the downhole tool, which allows you to calculate the angle between the inclination plane of the downhole tool and the vertical plane in which the main axis of the gyroscope lies. At the same time, the azimuth of the inclination plane of the downhole tool is determined using a magnetic compass. Then, the magnetic azimuth of the main axis of the gyroscope is calculated. Note that the process of deviating the downhole tool using a cord and measuring the azimuth of the inclination plane using a magnetic compass is a relatively long process that requires a certain amount of time to calm the vibrations of the suspended downhole tool and the magnetic arrow of the compass. In addition, a large number of steel structures near the venue of the exhibition, a change in their location in time, as well as variations in the Earth's magnetic field give their share of the error of the exhibition.

 The aim of the invention is to increase the productivity and accuracy of inclinometric work.

 This goal is achieved by the fact that the gyroscopic inclinometer is supplemented by a special ground-based exhibition system designed to determine the azimuth of the main axis of the three-degree gyroscope, which is part of the sensitive elements of the downhole tool. Knowing this azimuth allows you to reconcile the information obtained through the angle sensor of a three-stage gyroscope and the actual value of the azimuth of the inclination plane. The exhibition ground system contains the following components: a sensor unit, a calculation unit, a constant input unit, an analyzer unit, and a key element. The composition of the block of sensitive elements includes a two-component gyroscopic sensor of angular velocity and an accelerometer, according to which the calculation unit calculates the orientation parameters of the block of sensitive elements. Concretization of the conditions of the exhibition is carried out by a constant input unit, which is associated with the calculator unit. The analyzer block is designed to assess the quality of information coming from the block of sensitive elements and control the key element connecting the calculator block and the ground-based gyroinclinometer equipment. At the time of the exhibition, a block of sensing elements is attached to the body of the downhole tool in a strictly defined way, the primary information from which is transmitted to the calculator block, where the zenith angle and azimuth of the inclination plane of the sensing element block, and, accordingly, the downhole tool, are determined. The calculated parameters are presented in a form convenient for further use: either visually for the operator to work with them, or in the form of electrical signals for use in ground-based gyroclinometer equipment. In order to eliminate errors caused by any random movements of the downhole tool during the exhibition, the analyzer unit, controlling the key element, prevents the information from being output at this time.

 The drawing shows the composition of the gyroinclinometer complex.

 The downhole tool 1 is connected to the ground equipment 2 by a wireline 3. During the exhibition, the exhibition system of the downhole tool 4 is used. It includes a sensor unit 5, a calculator unit 6 and an analyzer unit 7. The sensor unit 5 includes a two-component angular gyro sensor speeds 8 and a two-component accelerometer 9, and their sensitivity axes are mutually parallel and perpendicular to the longitudinal axis of the downhole tool during the exhibition. The output signal of the analyzer unit controls the key element 10, which breaks the channel for transmitting information from the calculator unit to the ground equipment in cases of downhole tool movement. To enter information on the specific conditions of the exhibition into the calculator unit, the constant input unit 11 is used. The sensor unit 5 is connected to the calculation units 6 and the analyzer 7 by a communication line 12.

на оси чувствительности акселерометра. По этим сигналам блок вычислителя рассчитывает зенитный β и апсидальный γ углы блока чувствительных элементов
β arctg

γ arctg

-

Двухкомпонентный датчик угловой скорости 8 определяет составляющие ω_х и ω _y угловой скорости вращения Земли Ω₃ на те же оси чувствительности. Эти составляющие зависят от широты места исследований Φ, зенитного β и апсидального γ углов, азимута α
ω_x=Ω₃ (cosΦ·cosα·cosβ·cosγ+sinΦ·sinβ·cosγ-cosΦ·sinα·sinγ)
ω_y=-Ω₃ (cosΦ·cosα·cosβ·sinγ+sinΦ·sinβ·sinγ+cosΦ·sinα·cosγ)
Необходимые для расчетов величины g, Φ вводятся в блок вычислителя с помощью блока ввода констант 11. По алгоритму, построенному на основе приведенных выражений, блок вычислителя 6 определяет азимут плоскости наклонения скважинного прибора α Полученное значение азимута затем используется для определения азимута главной оси трехстепенного гироскопа. Если скважинный прибор в процессе выставки совершает непредусмотренные движения, то с чувствительных элементов снимаются сигналы, изменяющиеся во времени. Блок анализатора 7 определяет это и управляет ключевым элементом 10, который разрывает канал выдачи информации с блока вычислителя в наземную аппаратуру.The complex works as follows. Before the start of the well study, the downhole tool is suspended on a wireline 3. A sensing unit 5 is connected to the downhole device using a special attachment unit. The attachment unit provides the necessary location of the sensing unit relative to the longitudinal axis of the downhole tool. Using the communication line 12, the block of sensing elements is connected to the calculator block 6 and the analyzer block 7. The two-component accelerometer 9 generates signals proportional to the projections a _x and _y of the gravity acceleration vector

on the sensitivity axis of the accelerometer. Using these signals, the calculator block calculates the anti-aircraft β and apsidal γ angles of the sensor block
β arctg

γ arctg

-

The two-component angular velocity sensor 8 determines the components ω _x and ω _{y of the} angular velocity of rotation of the Earth Ω ₃ on the same axis of sensitivity. These components depend on the latitude of the study Φ, zenith β and apsidal γ angles, azimuth α
ω _x = Ω ₃ (cosΦ · cosα · cosβ · cosγ + sinΦ · sinβ · cosγ-cosΦ · sinα · sinγ)
ω _y = -Ω ₃ (cosΦ · cosα · cosβ · sinγ + sinΦ · sinβ · sinγ + cosΦ · sinα · cosγ)
The values of g and Φ necessary for the calculations are entered into the calculator block using the constant input unit 11. According to the algorithm constructed on the basis of the above expressions, the calculator block 6 determines the azimuth of the inclination plane of the downhole tool α. The obtained azimuth value is then used to determine the azimuth of the main axis of the three-stage gyroscope. If the downhole tool makes unforeseen movements during the exhibition, then signals that change in time are removed from the sensitive elements. The analyzer unit 7 determines this and controls the key element 10, which breaks the channel for issuing information from the calculator unit to ground equipment.

 After the exhibition, the block of sensing elements is disconnected from the downhole tool and the latter is lowered into the well to measure it in the usual way.

 A variant of the technical implementation of the ground-based exhibition system involves analyzing the signals of sensitive elements and blocking the output of information from a computer (computer) using software methods. The input block constants in this case the computer keyboard.

Claims (1)

 GYROINCLINOMETER COMPLEX, comprising a ground-based equipment and connected to its first input via a logging cable, a downhole tool having a three-stage gyroscope, the external axis of which is directed along the longitudinal axis of the downhole tool, characterized in that it is equipped with a ground-based exhibition system for the downhole tool, consisting of a tool attached to the downhole tool a sensor block, a calculator block, a constant input block, an analyzer block and a key element, wherein the sensor block contains two component gyroscopic angular velocity sensor and two-component linear accelerometer, the outputs of which are connected to the first input of the calculator block and the input of the analyzer block, the output of the constant input block is connected to the second input of the calculator block, the output of the calculator block is connected to the second input of the ground equipment through the key element, and the block output the analyzer is connected to the control input of the key element.

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