EP0465316A1 - Apparatus for stimulating production and for logging for non-eruptive wells - Google Patents

Abstract

In an equipped well (1) provided with a perforated tube (3) in its part passing through a production zone, there is lowered an apparatus comprising a production column (6) in two parts (6A, 6B) separated by an effluent pumping assembly (5) and a connection with a lateral aperture (21). At the lower end of the lower part (6B) of the column is arranged at least one measuring-instrument assembly (16) and, if appropriate, means (17) for homogenising the effluent before its treatment. The measuring assembly (16) is connected to the surface installation by means of a multi-conductor cable (18) passing from inside the column (6) to the outside in the region of the apertured connection (21). The pumping assembly (5) is positioned in a zone of the well accessible to the effluent produced, but sufficiently far from the most sharply deflected and/or most crowded well portions, so as to make it easier to install the pumping assembly and so as to prevent the risks of jamming or crushing of the cable (18) connected to the instrument assembly (16). <??>The invention is used, for example, for the study of oil-producing wells. <IMAGE>

Description

The present invention relates to an improved activation and measurement device for a non-eruptive well during production and in particular for a deviated well by designating by this term any well of which at least part has a more or less strong inclination with respect to the vertical and / or substantially horizontal parts.

In French patent applications 2,637,939 and EN. 89/04225, various embodiments of a logging activation and measurement device for wells equipped for production, of the non-eruptive type and in particular for deviated wells, are described. The devices described are particularly suitable for wells equipped for the production of petroleum effluents. They make it possible to determine the most favorable portions of the wells, especially when they cross heterogeneous reservoirs producing oil but also water and gas. The equipment of a well generally comprises a casing or casing tube held in place by cementing. Throughout the area intended for production, a perforated tube (or liner) is installed over at least part of its length which extends the casing. This perforated tube can possibly be cemented, the cemented annular being provided with passages putting the production area in communication with the tube. Inside the tube, a production column is lowered, formed by connecting successive sections. This column is provided with centering elements relative to the tube. Sealing means are arranged in the annular space between the column and the tube, so as to channel into the column all of the effluents produced by the production area. The well not being eruptive, means of activation or pumping are associated with the column and lowered into the well to suck the effluents. These activation means comprise for example a pump driven in rotation by an electric or hydraulic motor.

The device comprises at least one set of measuring instruments placed at the base of the production column for measuring the characteristics of part of the flows drawn by the pump. Isolation means are arranged around the column so as to separate the "liner" into two parts and to limit the measurements made to the effluents coming from only one of these two parts. The device may also include two measuring assemblies for separately measuring the characteristics of the flows coming from the two opposite parts of the tube. By lengthening or shortening the column, the logging device is moved so as to make measurements on the effluents flowing from the formation at different locations in the well.

In the French patent application EN. 90/03305, an improved logging device is described compared to the previous ones, for determining more precisely the characteristics of the multiphase flows coming from a production well, the improvement essentially due to the use of means for homogenizing the effluents before processing by measuring instruments.

In all the patent applications cited above, the activation pump and its drive motor are arranged at the base of the column very close to the sets of measuring instruments. It has been verified in use that this arrangement was not suitable for a number of production wells. The section of the activation pumps and the commonly used drive motors is indeed relatively large and in certain cases the previous activation and measurement devices could not be lowered in certain production wells whose section is smaller than the current sections. . In addition, the downhole motors are supplied by cables most often arranged in the annular space between the tube and the production column. In the deviated parts of the production wells, experience has shown that this mode of supply can present failures due to possible crushing of the supply cables.

The improved device according to the invention makes it possible, by avoiding the above-mentioned drawbacks, to carry out production logs in a non-eruptive well crossing an underground zone producing effluents, this well being equipped for the production of these effluents by means of a perforated tube in its part passing through said underground zone, the device of a production column connected to a surface installation, of means for closing the annular space between the tube and the production column, to isolate the one on the other the two parts of the tube on either side, pumping means to activate the production of the well by said column and means for measuring at least part of the effluents produced, arranged in the vicinity of the bottom end of the column.

• de moyens de pompage intercalés sur la colonne de production à une profondeur accessible aux effluents,
• d'un raccord à fenêtre latérale intercalé sur la portion de colonne entre les moyens de pompage et lesdits moyens de mesure; et
• d'un câble multi-conducteurs pénétrant à l'intérieur de la colonne au niveau dudit raccord à fenêtre latérale pour la liaison entre les moyens de mesure et l'installation de surface.

It is characterized in that it comprises the combination

• pumping means interposed on the production column at a depth accessible to effluents,
• a connection with a side window interposed on the column portion between the pumping means and said measuring means; and
• of a multi-conductor cable penetrating inside the column at the level of said side window connection for the connection between the measuring means and the surface installation.

In deviated production wells and in particular in wells passing through a production area with a relatively slight inclination relative to the horizontal, the length of the column portion between the location of the pumping means and the lower end of the column can be important. As this column portion is generally in the most horizontal part of the well, this avoids, in all cases where the motor means driving the pumping means are electric motors, the setting lengths of power cable most likely to get caught or crushed between the tube and the column.

The pumping means comprise for example a pump driven by an electric motor connected to the surface installation by an electric cable passing outside of said column.

The measuring means comprise for example a first set of instruments arranged on said column, for measuring the characteristics of the effluents coming from the upstream part of the tube, the furthest from the pumping means.

The measuring means may further comprise a second set of instruments for measuring the characteristics of the effluents coming from the downstream part of the tube, the closest to the pumping means.

The device may also include means for homogenizing at least part of the effluents produced before their treatment by the measuring means.

The multi-conductor cable can be provided with an electrical connection means to the measuring means, pluggable in a liquid medium and adapted to be moved by a stream of fluid along the production column.

• la Fig. 1 montre de façon schématique le dispositif selon l'invention positionné dans une portion de puits;
• la Fig. 2 montre un premier mode de réalisation du dispositif selon l'invention comportant un seul ensemble d'instruments de mesure pour mesurer les effluents amont et un système de connexion assurant une protection des câbles de liaison; et
• la Fig. 3 montre un deuxième mode de réalisation du dispositif comportant deux ensembles d'instruments de mesure pour mesurer les effluents amont et aval séparément, et un système de connexion analogue.

Other characteristics and advantages of the device according to the invention will appear better on reading the description below of two embodiments described by way of nonlimiting examples, with reference to the appended drawings where:

• Fig. 1 schematically shows the device according to the invention positioned in a portion of the well;
• Fig. 2 shows a first embodiment of the device according to the invention comprising a single set of measuring instruments for measuring upstream effluents and a connection system ensuring protection of the connection cables; and
• Fig. 3 shows a second embodiment of the device comprising two sets of measuring instruments for measuring the upstream and downstream effluents separately, and a similar connection system.

The well 1 shown in FIGS. 1 to 3 is drilled from a surface installation to an oil formation 2. In its lower part crossing the producing zone, it is deflected. It can be horizontal or very slightly inclined with respect to the horizontal for example. The well is equipped for production. In this lower part, a tube or "liner" 3 is installed for this purpose. This tube is provided with perforations 4 in its part which crosses the producing zone. It is a non-eruptive well whose production must be activated by a pumping system 5 lowered into the well interposed on a part 6A of a production column 6 formed by juxtaposition of tubular elements. The suction system 5 comprises an enclosure or casing 7 where a hydraulic pump 8 is arranged, the outlet 8A of which communicates with the part of the column 6A. The pump 8 is driven by an electric motor 9 also arranged in the enclosure 7.

The upper part 6A of the column 6, with the pumping system 5 fixed to its base, has a lower extension 6B. A sealing or sealing block 10 of a known type of the expandable type or with cups for example, is arranged around the extension 6B in the vicinity of its lower end. On order from the surface installation, if it is an expandable obturation block, it can be applied against the wall of the tube 3 so as to separate in a substantially sealed manner the portions of the well 11, 12 which are on both sides. By reference to the preferred direction of flow of the effluents in the direction of the surface, the zone 11 furthest from the orifice of the well is designated upstream and the zone 12 opposite on the other side with respect to the block 10 downstream. Centering means (not shown) are arranged around the production column 6 to facilitate its advancement in the well. The lower orifice 13 of the extension 6B opens on the side of the upstream well portion 11. Lateral openings 14 in the wall of the same extension 6B, on the opposite side of the sealing block 10, make the production column 6 communicate with the downstream part 12 of the well. The effluents entering the column 6B through the openings 13 and 14 flow towards the inlet 8B of the pump 8.

The measurements being carried out in this embodiment only on the effluents of the upstream part, the openings 14 can be made anywhere between the block 10 and the pumping system and in particular in the immediate vicinity thereof.

According to the embodiment of FIG. 2, the terminal part 15 of the production column contains a measuring assembly 16 comprising different instruments for measuring the upstream flows.

A first instrument is for example a tracer-ejector making it possible to measure the flow speed of the effluents coming from upstream. A second instrument is a density measuring device such as a gamma density meter. A third instrument is an electrical capacitance meter making it possible, for example, to determine the water content of the effluents.

As in the French patent application EN. 90/03305 above, we can associate with the measuring system a homogenization means 17 (a propeller or a turbine for example) to mix the different phases of the effluents from the formation, so as to obtain more easily interpretable measurements and thus facilitate the identification of areas of the well of interest for production.

This measuring assembly 16 is connected to a multi-conductor cable 18 by means of an electrical connector 19. Preferably, a pluggable electrical connector is used in a humid environment associated with a load bar and which makes it possible to establish connections. delayed in time between the measuring assembly 16 and the cable 18 and facilitate the installation of the device as will be seen in describing its operation. A connector of this type is described for example in French patent 2,544,013 or US patent 4,690,214. In the case where a homogenization means such as 17 is used associated with motor means, the power supply can be provided by conductors of the multi-conductor cable 18.

The cable 18 runs all along the portion 6B of the production column 6 to its opposite end in the vicinity of the pumping system 6. A side window connection 20 of the "side-entry-sub" type is preferably inserted between the casing 7 containing the pumping system 5 and the column portion 6B. The multi-conductor cable 18 passes through the window 21 of the connector 20 and goes up towards the surface installation outside the upper part 6A of the column.

The electric motor 9 for driving the pump 8 is supplied by a cable 22 which also goes up towards the surface installation in the ring finger between the casing C (or casing) cemented in the well and the upper part 6A of the column.

The pump motor 9 is for example an asynchronous motor and the power cable 22 connects it to a frequency converter 23 adapted to deliver to the asynchronous motor 9 an electric current of adjustable frequency and thus to vary the flow rate of the pump 8 depending on the amount of effluent produced. The multi-conductor cable 18 connects the measuring instruments of the assembly 16 to a control, acquisition and supply assembly 24 arranged on the surface. The multi-conductor cable 18 comprises conductors for the electrical supply of the measuring instruments of the measuring assembly 16 and possibly of the motor driving the homogenization means as well as other conductors for the transmission to the assembly 24 of the signals provided by measuring instruments.

With the arrangement described, many difficulties can be avoided which may arise in the most deviated part of the well and often also the most constricted. The pumping assembly 5 is lowered to a sufficient depth that the effluents produced can reach freely without activation. This depth varying as a function of the position of the measuring assembly 16 the location where the pumping assembly is often lowered into a portion of the well which is less deviated and more easily accessible. The multi-conductor cable 18 is protected by the production column throughout the lower portion of the well. Like the cable 22 for powering the motor 9, the cable 18 is found in the annular around the production column only in the upper part of the well, where it is least exposed to coincidences and crushing.

According to the embodiment of FIG. 3, the device according to the invention also comprises a second measuring assembly 25 for the effluents coming from the downstream zone 12. For this purpose, the portion of tube 15 beyond the block of obturation 10 and containing the first measuring assembly 16 of the upstream effluents is connected and communicates with a second column portion 26 provided with an internal partition 27 which delimits a compartment 28. An opening 29 makes compartment 28 communicate with the part downstream 12 from the well. Inside this compartment 28, there is also another means of homogenization (not shown) for mixing the downstream effluents before their treatment by the second measuring set 25. In this case, it is the second set of measurement 25 which is connected to the multi-conductor cable 18 by the electrical connector 19. The power supply of the measurement devices of the first measurement set 16 and the transfer of the measurement signals between the latter and the second measurement set 25 is provided by a multi-conductor cable 30 passing through the partition 27.

The compartment 28 communicates through an opening 31 with the part 6B of the production column. The upstream flow diverted by the partition 27 and measured and the measured downstream flow leaving through the opening 31, go up the column portion 6B to the inlet 8B of the pump.

At its upper part, the production column 6 may include a bypass on which a third measuring assembly (not shown) is installed to treat all of the effluents reaching the surface. This third measurement assembly 30 can be analogous to the preceding measurement assemblies 16, 25. It can also be a device of the test separator type which separates the phases before measuring them separately and which is placed on the surface outside the well.

The device according to the invention makes it possible to make measurements at different points of the production well, whether these are flows from the upstream zone (embodiment of FIG. 1) and / or from the downstream zone (mode of Figure 2). By comparison of measurements different measurement instruments of each set 16 and / or of the third surface measurement set, made on the effluents after their possible homogenization, one can easily determine the share of each phase in the three-phase-aspirated mixtures.

The comparison of the measurements made by the two sets 16, 25 with those made by the third set treating all of the effluents, corrected to take account of the conditions prevailing on the surface different from those prevailing in the production zone, makes it possible to validate the results by drawing up balance sheets.

• La portion de tube 15 contenant le premier ensemble de mesure 16 (le cas de la figure 2) ou éventuellement l'ensemble des deux portions de tube 15 et 26 contenant respectivement les deux ensembles de mesure 16 et 25 (cas de la figure 3), est raccordée à des sections de tube et par allongements successifs, on forme la partie inférieure 6B de la colonne de production.
• Après avoir fait passer le câble 18 et son connecteur 19 à l'intérieur de la colonne par la fenêtre du raccord à fenêtre latérale (SES) 21, on fixe celui-ci. On fait descendre le connecteur électrique 19 par gravité ou par pompage le long de la colonne 6B jusqu'à son enfichage au niveau des ensembles de mesure (16 et/ou 25).
• On fixe le carter 7 contenant la pompe. La fixation est effectuée de préférence par un raccord à écrou tournant et clavette de positionnement angulaire d'un type connu qui permet d'établir une liaison mécanique sans avoir à faire tourner le raccord 21 et le carter 7 l'un par rapport à l'autre.
• Les deux câbles 18 et 22 étant à l'extérieur, on fait progresser l'ensemble de mesure (16 et/ou 25) en allongeant la colonne 6A par ajouts successifs de sections, jusqu'à la zone du puits où l'on effectue les mesures.

The installation of the device in the production area is carried out as follows:

• The tube portion 15 containing the first measurement set 16 (the case of FIG. 2) or possibly the whole of the two tube portions 15 and 26 containing the two measurement sets 16 and 25 respectively (case of FIG. 3) , is connected to tube sections and by successive extensions, the lower part 6B of the production column is formed.
• After passing the cable 18 and its connector 19 inside the column through the window of the side window fitting (SES) 21, the latter is fixed. The electrical connector 19 is lowered by gravity or by pumping along the column 6B until it is plugged in at the measurement assemblies (16 and / or 25).
• The casing 7 containing the pump is fixed. The fixing is preferably carried out by a connector with a rotating nut and an angular positioning key of a known type which makes it possible to establish a mechanical connection without having to rotate the connector 21 and the casing 7 in relation to the other.
• The two cables 18 and 22 being on the outside, the measuring assembly (16 and / or 25) is advanced by lengthening the column 6A by successive additions of sections, up to the zone of the well where one performs measures.

The device thus constituted, the sets of measurement in the well along the producing zone by successive additions or withdrawals of tube sections and, by comparing the measurements carried out at these different points, one can determine the composition of the effluents and the variation of their flow as a function of the position in well. Care is taken to keep the pump in a position between the dynamic level and a depth compatible with the maximum admissible inclination.

Claims (6)

1) An improved activation and measurement device for a non-eruptive well (1) crossing an underground zone (2) producing effluents, this well being equipped for the production of these effluents by means of a tube (3) perforated in its part crossing said underground zone, the device comprising a production column (6) connected to a surface installation, closing means (10) of the annular space between the tube (3) and the production column (6) , to isolate from one another the two parts of the tube (3) on either side, means for activating the production of the well by said column and measuring means (16, 25) of at least part of the effluents produced, disposed in the vicinity of the lower end of the column, and being characterized in that it comprises the combination: - pumping means (5) interposed on the production column at a depth accessible to the effluents; - a fitting (20) with side window interposed on the column portion (6B) between the pumping means (5) and said measuring means (16, 25); and - a multi-conductor cable (18) associated with connection means (19) penetrating inside the column (6B) at the level of said connector (20) for the connection between the measurement means (16, 25 ) and the surface installation. 2) An improved device according to claim 1, characterized in that the pumping means (5) comprise a pump (8) driven by an electric motor (9) connected to the surface installation by an electric cable (22) passing through the outside of said column (6). 3) An improved device according to claim 1 or 2, characterized in that the measuring means comprise a first set of instruments (16) disposed on said column (6), for measuring characteristics of the effluents from the upstream part (11 ) of the tube (3), the furthest from the pumping means. 4) An improved device according to the preceding claim, characterized in that the measuring means further comprise a second set of instruments (25) for measuring characteristics of the effluents from the downstream part (12) of the tube, the closest to pumping means. 5) An improved device according to one of the preceding claims, characterized in that it further comprises means (17) for homogenizing at least part of the effluents produced before their treatment by the measuring means. 6) Improved device according to one of the preceding claims, characterized in that the multi-conductor cable (18) is provided with an electrical connection means (19) to the measurement means (16, 25), pluggable in liquid medium , said connection means (19) being adapted to be moved by a stream of fluid along the production column (6).

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