RU2353955C1 - Facility for horizontal well logging - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: facility for horizontal well logging contains lowered into well autonomous geo-physic modules connected between them into assembly, to upper part of which there is connected device for connection of assembly with flow string; facility also contains surface complex including depth gauge and personal computer; also assembly contains modules of gamma-logging, of three-probe neutron-neutron logging, of multi-probe electric side logging, of wave acoustic logging, of acoustic profile gauge, and of inclinometer; in lower part of assembly there is installed nozzle for outlet of well washing fluid into annular space at well washing, and each autonomous geo-physic module contains autonomous supply unit, signal conversion and memory units.

EFFECT: obtaining efficient complex of apparatus for logging horizontal bore holes of wells and upgraded information value of geo-physic survey of horizontal wells at simultaneous reduction of break down rate of this kind of operations.

4 cl, 2 dwg

Description

The invention relates to the field of geophysics, and in particular to the field of carrying out a complex of geophysical studies of horizontal wells in the search and exploration of mineral deposits, and can be used for simultaneous electrical and radioactive logging, inclinometry, acoustic logging, etc. in deviated and horizontal wells.

Known (SU, copyright certificate 1173371) is a borehole logging complex comprising a logging cable, a downhole tool docked to the cable, mounted centrally with the possibility of longitudinal movement relative to the cable, including elastic runners connected to the upper and lower movable sleeves, and a stop-pusher mounted on the cable moreover, between the indicated bushes an additional support disk is installed.

A disadvantage of the known device should be recognized as low information content of the information received.

The closest in terms of the essential features of the claimed invention can be recognized as the Gorizont hardware-methodical complex (developed by VNIIGIS, Oktyabrsky) (Scientific and Technical Bulletin of AIS Karotazhnik - issue 36, Tver, 1997, p. 85), intended for exploration of horizontal wells using tools lowered on drill pipes. Structurally, the downhole tool consists of seven unified modules having common power, control and data transmission buses. The modules are placed in a fiberglass case, which, using a steel adapter, is attached to a drilling tool with the possibility of delivering horizontal wells without the use of a logging cable to a given depth of research. It is possible to flush when lowering the drilling tool to the bottom. All measurements are carried out in one descent, which gives a rigid alignment of the recording points of the GIS methods with each other. The ground equipment used includes a depth gauge, a weight sensor, a personal computer, an object interface device (USO), and a dot matrix printer.

The AMK "Horizont" can be recognized as the disadvantages of a limited amount of information due to the used set of well logging methods (research complex), which is due to the design of an autonomous integrated downhole tool, the diameter of the downhole tool (180 mm) requires mandatory development of the well before the launch of the complex, which increases the total time by research, the presence of a single power supply, a memory unit and a control unit, which leads to a failure of the entire system in the event of any malfunction, while with a single module more than 100 kg and more than four meters in length require the use of loading and unloading and vehicles.

Work with AMC "Horizon" showed its certain effectiveness in the study of horizontal wells, allowed to work out the measurement technology, methodological methods for processing, interpreting and providing information obtained in terrigenous and carbonate sections. However, analysis of the obtained materials shows its low suitability for work in reservoir conditions with varying characteristics. It has been established that if within one oil reservoir its properties (porosity, clayiness, oil saturation and permeability) vary widely, then the set of geophysical methods (blocks) used does not provide an unambiguous interpretation of the measurement results. In addition, for a more accurate interpretation, it is necessary to take into account the material composition of the rocks, their density, fracture, etc. This requires a wider range of geophysical methods.

The technical problem solved by the developed technical solution is to obtain an effective set of equipment for the study of horizontal wellbores.

The technical result obtained by the implementation of the developed technical solution consists in increasing the information content of geophysical surveys of horizontal wells while reducing the accident rate of this type of work.

To achieve the technical result, it is proposed to use a device for logging horizontal wells containing autonomous geophysical modules lowered into the well, interconnected into an assembly, to the upper part of which a means is connected to connect the assembly to the drill pipe string, as well as a ground complex, including a depth gauge, a sensor weights, a personal computer and a unit for determining the position of the wedges. The assembly contains modules of gamma-ray logging, three-probe neutron-neutron logging, multi-probe electric side logging, wave acoustic logging, acoustic profiler, inclinometer installed in any sequence. A nozzle is installed at the bottom of the assembly for flushing drilling fluid into the annulus, and each autonomous geophysical module contains an autonomous power supply, signal and memory conversion units, the assembly may also additionally contain a spectrometric gamma-ray logging module and / or a lithoplastic gamma-gamma-ray logging module also containing an autonomous power supply, signal and memory conversion units,

As a result of the development of this device, it was possible to solve geophysical problems with obtaining new technical results due to the expansion of the set of simultaneously applied GIS methods (research complex), which is unlimited and determined by the tasks to be solved by freely forming an assembly of autonomous geophysical modules and reducing the accident rate. This complex, called AGS, includes the following modules: AGK (gamma-ray logging), ANK-3 (three-probe NOC), AEC (multi-probe electric lateral logging), AWAC (wave acoustic logging), AKP (acoustic profiler), AI ( inclinometer) and can be supplemented to determine the parameters in complex reservoirs with the following modules: ASGK (spectrometric GK), AGGK (litho-density gamma-gamma-ray logging) and a caliper-profiler module.

The disadvantages characteristic of the technical solution selected as the closest analogue are eliminated in the developed device, namely:

1. The set of applied modules allows you to qualitatively solve the problem of isolating reservoirs, determining porosity, permeability, density of rocks, material composition, fracturing, determining water-saturated reservoirs within a reservoir with changing characteristics, as well as determining the diameter of the well and the technical condition of the wellbore, which is absent in the nearest analogue.

2. Each model contains its own power source, storage unit, control unit, which allows one module to receive data from other modules and to solve the problem.

3. The design of the modules allows flushing the well in the research process, thereby eliminating the sticking of the modules and the drilling tool in the well, i.e. reducing the possibility of an accident to a minimum.

Autonomous horizontal logging equipment contains autonomous geophysical modules with a diameter of 102 mm for exploring wells with a diameter of 120-216 mm and 168 mm for exploring wells of 216 mm or more, interconnected into an assembly, to the upper part of which an adapter is connected to connect the assembly to the drill string pipes, and in the lower part of the device (nozzle) for flushing drilling fluid into the annulus.

As mentioned earlier, each autonomous geophysical module contains autonomous power supplies, signal and memory conversion units.

During the development of the device, it was found that full information about a horizontal well includes the following:

1. Separation of rocks exposed by a horizontal well according to the lithological composition, which can be carried out using:

- litho-density gamma-gamma-ray logging - based on the spectral analysis of the recorded spectra of rocks that differ in density, determine the lithology and type of rocks;

- acoustic module (AVAK) - the lithology and physical and mechanical properties of the rocks are determined by the speed of passage of acoustic waves in the rocks;

- these two modules differ in physical fundamentals and complement each other.

2. Isolation in the exposed thickness of the reservoir, the determination of their porosity, which can be carried out using:

- three-probe neutron-neutron logging - determines the hydrogen content of the rocks and, accordingly, porosity (the use of the three-probe modification allows you to get rid of the influence of borehole conditions at different diameters of the well and obtain more reliable information);

- acoustic module (AVAK) - measures the velocities of longitudinal, transverse and Lemb-Stoneley waves in order to determine the porosity and permeability of rocks;

- module lithoplastic gamma-gamma-ray logging - based on the density of the rocks determine the type of rock and its porosity.

3. The determination of clay, which can be carried out using:

- GK module - based on the measurement of natural radioactivity, the clay content of the rocks is determined;

- module of spectrometric HA - based on spectral analysis of the natural radioactivity spectra of the rocks, the content of radioactive minerals containing compounds of potassium uranium and thorium is determined, which contribute to the natural radioactivity and, accordingly, to clay content, which allows for clay correction.

4. Determination of saturation, which can be carried out using:

- a five-probe electric logging module based on an analysis of rock resistance to obtain separation of the rocks according to water saturation and oil saturation.

5. Determination of the technical condition of the wellbore and its diameter, which can be carried out using:

- AKP module, which provides measurement of six wave images obtained from measuring sensors located at three levels at an angle of 60 degrees. Six wave pictures are measuring six radii.

These tasks are sufficient to obtain information about the horizontal wellbore. The set of proposed methods solves these problems to a rather high degree.

Figure 1 shows the layout diagram of the assembly of modules in the open hole of a horizontal well, figure 2 shows a block diagram of the ground equipment of an autonomous equipment complex, the following notation being used: drill pipe string 1, drill pipe sub 2, ANC module 3, AEC module 4, AGC module 5, AVAC module 6, ACP module 7, ASGK module 8, AGGK module 9, AI module 10, nozzle 11, depth sensor 12, tool weight sensor 13, rotor wedge position sensor 14, information collection unit 15 , downhole modules 16, computer 17, network th cable 18.

All modules and units of the device work in a standard way.

Autonomous equipment operates as follows. On the bridges of the drilling, programming is carried out for the operation and assembly of autonomous downhole geophysical modules that implement the necessary GIS complex. An adapter is connected to the top of the assembly to connect the assembly to the drill pipe string. The auxiliary winch assembly is raised above the wellhead and slowly lowered into the well to the upper module, into which the S-plate is inserted and then lowered to the surface of the rotor barrel. The S-plate also holds the entire ligament and weighs it in the well and prevents it from turning around its axis.

Next, they build up another candle of the drilling tool and its usual descent to the bottom of a horizontal well. If necessary, flush the well during the descent. The process of lowering autonomous equipment to the bottom of a horizontal well and logging is accompanied by recording information from ground-based sensors into the computer: depth, weight of the tool, position of the rotor wedges (Fig. 2). Autonomous modules during descent are switched on to work at the programmed time, and the geophysical data is recorded in the memory of the modules. When the bottom of the well is reached, the well is flushed through the internal channel in the modules and the nozzle to remove residual sludge from the wellbore, and then lift the assembly with the record necessary for repetition.

Dismantling of the modules is possible both in the vertical position, when landing the modules on the S-plate, and in the horizontal on the drilling bridges. After disassembling the modules, the recorded information is read through the network wire to the computer, combined with information from ground sensors on a time scale recorded in the modules and in the computer and converted to LAS format as a function of depth.

When studying the 4866 horizontal well at the Samotlor field with this complex, as a result of processing the obtained data, oil-saturated reservoirs were identified in the depth interval 2272.2-2657.7 m, with an oil saturation coefficient of 69.9%. As a result of testing this well, an inflow of oil was obtained with a flow rate of 300 tons / day.

The developed device in relation to the closest analogue has the following additional advantages:

- the ability to flush the well at any stage of logging due to the presence of a channel for the passage of drilling fluid in all modules;

- the use of a complex of multi-depth lateral logging probes to highlight reservoirs, to determine the electrical resistivity of the reservoirs;

- registration of wave fields of acoustic logging, statistical processing of target waves, study of the velocity characteristics of the section, determination of porosity and permeability;

- determination of the diameter of the trunk of the studied wells from 120 to 320 mm;

- determination of the mineralogical composition of rocks.

- the assembly operation of the modules can be carried out both in horizontal and vertical position and does not require special handling equipment, since the weight of the module does not exceed 60 kg and a length of 3 m.

Claims (4)

1. A device for logging horizontal wells containing autonomous geophysical modules lowered into a well connected to each other in an assembly, to the upper part of which is connected a means for connecting the assembly to the drill pipe string, as well as a ground complex, including a depth gauge and a personal computer, characterized in that the assembly contains modules for gamma-ray logging, three-probe neutron-neutron logging, multi-probe electric side logging, wave acoustic logging, acoustic profiler, Inc. inometra, wherein the bottom of the assembly is set to nozzle exit flushing drilling fluid in the well annulus during washing, and each module contains self geophysical autonomous power supply, power signals and transform memory. 2. The device according to claim 1, characterized in that the assembly further comprises a gamma-ray spectrometric module. 3. The device according to claim 1, characterized in that the assembly further comprises a module of lithium-density gamma-gamma-ray logging. 4. The device according to claim 1, characterized in that the assembly further comprises a caliper-profiler module.

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