MXPA99005148A - Transport of an instrument along a well do not see - Google Patents

Abstract

The present invention relates to a transport apparatus for transporting, at least, a logging probe through a geological formation traversed by a horizontal or highly deviated borehole. The transport apparatus comprises a pair of arched cams mounted with a pivot in a support member, a means for deflecting the arcuate surface of each cam and bringing it into contact with the borehole wall, and actuators operatively connected to each cam. In the transport apparatus, a diagnostic probe is connected. When either of the actuators is activated in an initial direction, the cam connected to the activated actuator is linearly moved forward and the arched surface of the cam slides along the wall of the borehole. When any of the actuators is activated in a second direction, the activated actuator pulls the cam connected backward and the deflection means forces the arcuate surface of the cam to lock against the wall of the borehole. Once the cam is stopped, the additional movement of the actuator propels the transport apparatus and the forward logging probe along the highly deviated or horizontal borehole.

Description

TRANSPORT OF AN INSTRUMENT ALONG A NON-VERTICAL WELL INTERFERENCE TO RELATED APPLICATIONS. - This application is, in part, a continuation of the pending US Pat. 08 / 924,672, filed on September 5, 1997, and also claims the benefit of the US provisional application. 60 / 088,645, filed on June 9, 1998.

DATA OF THE INVENTION In general, the present invention relates to an instrument transport system and, in particular, to a method and apparatus for transporting an instrument along a non-vertical well. In order to economically produce hydrocarbons from a deposit, the method of drilling a well, through a geological formation, which deviates from the traditional vertical orientation, is increasingly used. The deviation can be the result of drilling a borehole using an acute angle or angle that gradually moves away from the vertical axis. The deviation can also be the result of drilling a borehole that extends horizontally from the vertical axis. In general, the formations surrounding said horizontal and deviated boreholes are probed and the wells completed with instruments that are lowered into the borehole in a drill string or cable. These instruments generally depend on the force of gravity to be transported along the well or borehole. However, when drilling the borehole at a sufficiently high angle, or when the inner surface of the well is particularly rough, the force of gravity is not sufficient to overcome the friction of the instrument and the drilling cable against the surface. internal of the well. So far, rigid devices, such as drill pipes and coils, have been used to push logging probes along horizontal and highly deviated boreholes. However, the transport of drill pipes and coils is not the most suitable for all conditions. For example, the connection and disconnection of drill pipes can be very labor intensive and costly, and the transport of coils is limited due to the helical deformation of the pipes. Previously, attempts to propel instruments along a deviated sounding included equipping said instruments with driven wheels, for dragging the instruments along the well, or holding feet, extended by hydraulic means from the outside of the instrument. However, the integration of these systems into the diameter of some well instruments can be difficult, resulting in solutions that are far from optimal. For example, the integration of motors powerful enough to drive the wheels that extend from the instrument, often requires that the motors be coupled to their respective wheels by means of 90-degree gearboxes. The distance at which the clamping feet can extend from the surface of the instrument is typically limited by the limitations of integration and the required length of the hole of a related actuator cylinder mounted through the instrument. Many of the means developed to drive inspection and cleaning machines of large ducts, along the hole of the ducts, are not suitable for the transport of instruments along drilling, simply because of the size restrictions imposed by the small diameter of the holes. The tubing of many wells has a maximum diameter of four to six inches (10 or 15 cm). In addition, the electrically operated systems located at the bottom of the well should be as efficient as possible to reduce the cable current and the losses related to the transport of said current through cables of exceptional length. Unfortunately, the increase in the diameter of the cable to supply more power, either hydraulic or electrical, also increases the force required to pull the heavier cable along the hole in the horizontal well. Thus, a more economical and convenient means of transporting instruments through the horizontal or highly deviated portion of a borehole is preferable. Ideally, an apparatus would be capable of easily adapting to a wide range of internal diameters along the same well. Preferably, a transport instrument that attaches to the inner surface of the well would also be effectively decoupled from the surface of the well when the power supply is interrupted or when a foreseeable failure occurs to allow the instrument to recover without any difficulty.

SUMMARY OF THE INVENTION The current invention offers an improved bottomhole transportation system for transporting instruments such as logging probes along a non-vertical well.

According to one aspect of the invention, an apparatus for transporting an instrument along a non-vertical well is provided. The apparatus includes an elongate housing, adapted to be connected to an instrument to be transported, a cam anchor, arranged to extend laterally from the housing and pivotally connected to the housing at a linearly displaceable pivot point, and an actuator operatively connected to the housing and designed to linearly displace the pivot point of the cam anchor along the housing. The surface of the camshaft anchor is arched to fit, by sliding, to an inner surface of the well as the pivot point of the camshaft anchor is displaced in an initial direction, and to attach to the internal surface of the shaft as the pivot point of the cam anchor is displaced in a secondary direction, to transport the instrument along the well. Preferably, the apparatus has a first and second of these cam anchors attached to the housing, at respective pivot points spaced along the housing, with the arched surfaces of the cam anchor cams aligned in a common direction. The first and second of these actuators have been designed to displace, separately, the pivot points of the first and second cam anchors respectively, in order to transport the instrument along the well. In some preferred physical representations, the cam anchor is adapted to rotate about its pivot point to a retracted position, with the arched surface of its cams decoupled from the inner surface of the well. In some cases, a spring is installed to deflect the cam anchor to its retracted position. In some physical representations, the cam anchor has a pair of anchoring members, oriented in the opposite direction, pivoted to the housing at a common pivot point and arranged so as to simultaneously engage opposite portions of the inner surface of the anchor. water well. It is preferable that both anchoring members are adapted to rotate about their common pivot point, to retracted positions, with the arched surfaces of their cams decoupled from the inner surface of the well, the apparatus having a spring adjusted to deflect both anchoring members. to their retracted positions. In some cases, the cam anchor has a plurality of projections extending from the arcuate surface of its cams to be fixed to the inner surface of the well. These projections are preferably composed of a rigid and durable material, such as carbide.

The inner surface of the well may consist of soil or well tubing, for example. In some physical representations, the transported instrument contains a sensor of a log, which responds to a characteristic of the bottom of the well, and electronic systems adapted to activate the actuator. Preferably, the apparatus is adapted to automatically retract the cam anchor to its retracted position when an interruption of the power supply occurs. In a presently preferred physical representation, the apparatus includes a retraction assembly comprising the cam anchor and an arming piston. The retraction assembly can be linearly displaced along a slot in the housing by the actuator between the front and rear positions, with the arming piston extending from the retraction assembly and adjusted to engage a housing surface at one end of the housing. slot, and to be compressed by the housing as the retraction assembly is moved to its front position, thus forcing the cam anchor to be placed in its extended position. In some physical representations, the retraction assembly includes a housing for the retraction assembly, a retraction piston and a tension spring. The retraction piston is installed within a hole in the retraction assembly housing and connected to the pivot point of the cam anchor. The retraction piston communicates by hydraulic means with the arming piston and is adapted to move within the bore of the housing in order to move the pivot point when the arming piston is compressed. The tension spring is connected to the housing of the retraction assembly and to the cam anchor and adjusted to force the cam anchor to move into its extended position when the arming piston is compressed.

In a preferred physical embodiment, the retraction assembly includes a first unidirectional check valve, adjusted to allow a hydraulic flow from the arming piston to the retraction piston when the arming piston is compressed, a normally open solenoid valve, adjusted to allow a hydraulic flow of the retraction piston to the arming piston in the absence of electrical voltage in the solenoid, and a spring adjusted to deflect the retraction piston to a retracted position of the cams. Preferably, the apparatus also defines a compensation cavity which is communicated by hydraulic means with the retraction piston and which is • adjusted to receive hydraulic fluid from the retraction assembly when the solenoid valve opens and the percussion piston is blocked to prevent it from fully extending.

According to another aspect of the invention, there is provided a method for transporting an instrument, along a non-vertical well, to a predetermined position. The method includes the following steps: < a) connect the apparatus previously described to an instrument to be transported; (b) Lower the instrument and the apparatus into the non-vertical well; (c) activating the actuator to displace the pivot point of the cam anchor in the initial direction to slide the surface of the cam anchor along the inner surface of the well; (d) activating the actuator to displace the pivot point of the cam anchor in the second direction to grip the inner surface of the well and transport the instrument along the well; and (e) repeating steps (c) and (d) until the instrument is transported to a predetermined position.

In some physical representations of the inventive method, in which the apparatus has two sets of cam anchors and related actuators, the preceding steps (c) and (d) include: i) activating both actuators to move the pivot points of both anchors of cams in the second direction in order to couple the cam anchors against the internal surface of the well; and ii) sequentially activating each actuator to sequentially shift the pivot points of the cam anchors in the initial direction in order to transport the instrument along the well. In some cases, the preceding step i) includes activating an actuator to move the pivot point of a cam anchor in the initial direction, simultaneously activating the other actuator to displace the pivot point of the other cam anchor in the second direction . In some other physical representations of the inventive method, in which the apparatus has two sets of cam anchors and related actuators, the method includes, between steps (b) and (c) above, activating both actuators to move the pivot points of both cam anchors in the second direction in order to couple the cam anchors against the inner surface of the well and, while maintaining a cam anchor coupled to the inner surface of the well, perform steps (c) and (d) ). In these physical representations, steps (c) and (d) include activating the actuator associated with the other cam anchor to alternate the pivot point of the other cam anchor in the first and second directions in order to transport the instrument along the well. That cam anchor can be diverted to the inner surface of the well by a spring. In some physical representations, the transported instrument contains a sensor of a graph that responds to a characteristic of the bottom of the well. In some cases, the transported instrument also contains electronic systems adapted to activate the actuator. Fortunately, the anchors of the present invention do not require the application of large amounts of power to force them to be placed actively against the inner surface of the well. Basically, the arched surfaces of its cams are passively coupled to the wall of the tubing, being the only coupling load applied by a relatively small spring. Most of the normal load developed between the cam anchors and the tubing comes from the frontal transport force applied by the actuator. Thus, the complexity and cost of an individual power device is not required to extend the cams, since the cams are automatically fixed by being dragged in one direction and released automatically when pushed in the other direction.

Furthermore, the invention presents a means for automatically retracting the cam anchors in the event of an interruption of the power supply, thus avoiding having to break the cam anchors to remove the instrument chain from the well. The invention can provide an efficient and practical means for transporting instruments, such as logging probes or well completion instruments, along a non-vertical well. Other advantages of the present invention will be apparent from the following description of the accompanying drawings. It is understood that the illustrations should be used for illustrative purposes only and not as a definition of the invention.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS Figure 1 is an illustration of an instrument string in a deviated borehole. Figure 2 is an illustration of the transport apparatus of the present invention. Figures 3A and 3B depict the transport apparatus within a borehole with a small and large diameter. Figures 4A-4C illustrate the position, velocity and force versus time for the continuous movement of a transport apparatus, according to the invention. Figure 5 illustrates a second string of instruments with a transport apparatus equipped with cam anchors adapted to automatically retract. Figure 6 is a side view of one of the conveyor probes of Figure 5. Figures 7 and 8 are a perspective and side view, respectively, of the retraction assembly of the conveyor. Figures 9 and 10 are transverse views of the retraction assembly with the cam anchors in the retracted and extended positions respectively, taken along the line 9-9 in Figure 8. Figure 11 is a perspective view of the assembly of retraction, shown an exploded view of the section of his anchor. Figure 12 is a functional diagram of the hydraulic elements of the conveyor.

Figure 13 is an enlarged view of the section of the clamp shown in Figure 9. Figure 14 is an exploded view of the section of the clamp of the retraction assembly.

Figures 15 and 16 together form a single transverse view of the internal structure of the actuator and compensator sections of the conveyor. Figures 17A and 17B are a side and a front view, respectively, of the outer portion of a first cam member. Figure 17C is a side and front view of the outer portion of a second cam member. Figure 18 is a functional diagram of the electronic cartridge of the instrument chain of Figure 5, including an optional logging sensor.

DESCRIPTION OF PHYSICAL REPRESENTATIONS Figure 1 - is a schematic illustration showing the descent of an instrument chain 10 into a deviated well 12. The well 12 is typically lined with a steel casing 13, cemented in position in the formation, and may also include the production pipe. However, in the present invention it is contemplated to have a well with an open orifice that may or may not be piped. The instrument chain 10 includes at least one diagnostic probe 14 connected to a transport apparatus 16. The instrument chain 10 also includes an electronic cartridge 17 for controlling the transport apparatus 16. In some cases, the electronic cartridge 17 also controls the logging probe 14 and, in some cases, the cartridge includes one or more logging sensors and functions as a logging probe 14. The string of instruments 10 is suspended from a shielded cable 18 containing a lined electrical conductor (a single cable) ) to transmit power and electrical control signals from the well surface to the instrument chain, and data telemetry from the instrument to the surface. On the surface of the well a winch (not shown) is used to lower and raise the string of instruments 10 in the vertical portion of the well, and to pull the string of instruments 10 in the vertical portion of the well, to pull the string of instruments along the non-vertical portions of the well.

In some cases, the diagnostic probe 14 is located at a distal end of the instrument chain 10, as shown, in front of the transport apparatus 16, such that the transport apparatus 16 pushes the diagnostic probe 14. along the diverted portions of the well. In other cases, the diagnostic probe 14 is located at a proximal end of the instrument chain 10, behind the transport apparatus 16, such that the apparatus draws the diagnostic probe along the well.

Figure 2 is a schematic illustration of a physical representation of a transport apparatus 16 for transporting, in a single direction, a logging probe along a deviated well. The apparatus 16 has two sets of cam actuators mounted within a common housing 19. A set of cam actuators consists of a cam anchor 20 with two opposingly oriented cam members 26a and 26b, a support frame 22 and an actuator 24. The linear actuator 24 is designed to linearly move the support frame 22 along the housing 19 (ie, in a direction extending along the well), thus displacing a pivot point 40 in which they are positioned. the two cam members of the cam anchor 20 are installed by means of a pivot in the support frame 22. The cam members 26a and 26b have arcuate outer surfaces 21 composed of a strong material, resistant to corrosion and wear, as it is. stainless steel, to be coupled to the inner surface of the well. A compression spring 28, which extends between the cam members 26a and 26b, is adjusted to deflect the arcuate surfaces of the opposingly oriented cam members and bring them into contact with the inner surface of the well. However, other deflection means such as torsion springs or tension springs may be employed. In this invention it is contemplated to use other means for deflecting the cam anchor 20 against the borehole, including systems activated by electromechanical or hydraulic means. A second set of cam actuators, consisting of a cam anchor 20 a support frame 22 'and an actuator 24 has a construction similar to that previously described. The arched surfaces of the cams 21 of the cam members of the cam anchor 20 'are provided with projections 29, such as toothed or corpuscular members, for better fixing on the inner surface of the well. The projections 29 consist of a material with properties of high rigidity and resistance to abrasion, such as tungsten carbide. In other physical representations, the cam anchor 20 has similar projections. Referring still to Figure 2, the actuator 24 includes a motor 30, adjusted to rotate a ball head screw 32, coupled to the ball head screw through a reduction gearbox 34. On the other hand, the actuator 24 it may consist of another means for linearly displacing the support frame 22, such as a hydraulic piston coupled to a motor-driven hydraulic pump. When the motor 30 is rotated in one direction, the ball screw 32 linearly displaces the support frame 22, together with the pivot point 40, forward. During this displacement, the arcuate surfaces of the cam members 26a and 26b are free to slide along the wall of the borehole. When the motor 30 is rotated in the opposite direction, the ball screw 32 pulls the turning point 40 backward, closing or locking the arcuate surfaces of the cam members 26a and 26b against the wall of the borehole and propelling the conveyor and diagnostic probe forward. In various physical representations described in more detail below, the actuators 24 and 24 'cooperate to move the instrument along the well. The transport apparatus 16 is closed or slidably coupled to wells with various internal diameters. Figures 3A and 3B depict the cam anchor 20 within a tubing with a relatively small and large diameter., respectively. The contact angle,?, Is defined between an "A" direction, perpendicular to the hole of the tubing, and a line, "B", which extends from the pivot point 40 to the "C" point where the cam member 26b it is coupled to the tubing 13. The maximum contact angle required to firmly close the cam anchor 20, without sliding, against the wall of the borehole, is related to the friction characteristics between the cam 20 and the wall of the borehole 12. The contact angle tangent? Must be smaller than the static coefficient of friction between the surface 21 and the tubing 13, so that the friction between the surface of the cam anchor and the tubing prevents slippage when the actuator pulls the cam anchor in the "locked" direction Because the contact point "C" is at the rear of the pivot point 40, the cam anchor slides freely along the surface of the tubing 13 when it is moved in the direction of "slip". Currently, we prefer a contact angle of about 22 degrees, which corresponds to a coefficient of friction of approximately 0.4. To accommodate the different diameters of the tubing, the arched surfaces of the cams 21 are formed in such a way that the contact angle? it remains constant when the members of the cams 26a and 26b rotate inwardly or outwardly around the pivot point 40. It is preferable that the actuators 24 and 24 'are activated in a controlled manner to cause movement of the cam anchors 20 and 20. ', so that they can move the chain of instruments cooperatively along the well. To prevent the instrument from moving backward (ie towards the hole in the well), due to the reaction to the forward slip of a cam anchor or to the tension of the cable 18 (Figure 1), a cam anchor is locked against the borehole at all times. In other words, when one cam anchor 20 'or 20 is carried forward, the other cam anchor remains locked against the borehole wall, preventing the instrument chain from moving backward. Figures 4A-4C illustrate, velocity and force versus time for continuous movement of the transport apparatus of the. Figure 2, to which we also refer. In the rest position of a physical representation, at time t = 0, the ball screw 32 of the first actuator 24 is fully extended, while the ball screw 32 'of the second actuator 24' is completely retracted. To transport the instrument chain forward, the motor .30 of the first actuator rotates in one direction and retracts the ball head screw 32, dragging the cam anchor 20 backwards and thereby locking the arched surfaces of the cams 21 of the cam 20 against the probing well wall 12 and propelling the transport apparatus and forward logging probe. Simultaneously, the motor 30 'the actuator 24' rotates the ball screw 32 'to linearly displace the pivot point 40' of the cam anchor 'forward with the din to slide the cam anchor 'forward along the wall of the tubing.

Then these actions are reversed, so that the first • motor 30 rotates in the opposite direction to slide the anchor of the cams 20 forward, while the second motor 30 'retracts the support frame 22' to pull the cam anchor 20 'rearwardly, thereby locking the arched surfaces of the cams 21 'of the cam anchor 20' against the wall of the borehole and propelling the transport apparatus and the diagnostic probe further forward. By moving the anchors of the cams forward a little more quickly than when they are dragged back, you can configure the synchronization of the two actuators with a slight overlap of their traction strokes, so that the net frontal movement of the chain of instruments is continuous, as shown in Figure 4B. Since the amount of electric power available to the actuators is limited through the cable 18 (Figure 1), the maximum tensile force developed by the actuators will be lower at higher traction speeds, as shown in Figure 4C. In another operating sequence, the cam anchors 20 and 20 'are operated first simultaneously and then sequentially. The actuators 24 and 24 'are activated simultaneously to draw both cam anchors backwards, thereby locking the arched surfaces of their cams 21 against the wall of the borehole and propelling the instrument chain forward. Next, the actuators 24 and 24 'are sequentially activated to move each cam anchor forward, after which both actuators retracts the cam anchors together again to transport the instrument chain forward. These steps are repeated until the logging probe is transported to a predetermined position. In a third operating sequence, an actuator is alternated to transport the string of instruments along the well progressively, while the other actuator remains stationary, with its corresponding cam anchor locked against the wall of the tubing to prevent it from moving backward . Figure 5 shows another string of instruments 50, comparable to the instrument string 10 in Figure 1, but having (from the bottom to the top) a logging probe 14, two instrument carrying probes 52, an electronic cartridge 54 and an adapter cable 56. Although only one logging probe 14 is shown, it should be understood that the string of instruments may contain multiple logging probes or other such devices for transporting them along a non-vertical well. Each conveyor 52 has two cam anchors 58, each cam anchor having opposite cam members 60a and 60b. Each conveyor also has a single actuator (not shown) to move its two cam anchors together. Each cam member 60a and 60b has an arcuate distal cam surface 62 for coupling to the inner surface of the well casing, as described above with respect to the physical representation of Figure 2, such that the cam anchors they slide freely along the surface of the tubing when they move forward, indicated by the arrow "F", but they lock against the tubing surface when they are dragged back, indicated by the arrow "R".

Referring to Figure 6, each conveyor 52 consists, from top to bottom, of an upper front section 64, a section of the compensator 66, a section of the actuator 68, a section of the rail 70 and a lower front section 72. The section of the rail 70 contains a retraction assembly 76 mounted within a slot 78 that extends through opposite sides of the rail section. The retraction assembly 76 contains the cam anchors 58 and is displaced longitudinally along the slot 78 by an actuator that is in the section of the actuator 68. As explained below, with respect to Figures 15 and 16. Each transporter probe facilitates electrical communication along the length of the probe, to transmit power and control signals to and from the diagnostic probes or other connected devices.

Referring to Figures 7 and 8, the retraction assembly 76 consists of, from left to right, a clamp of the actuator bar 80, a hydraulic block 82, a section of anchors 84 and a section of the reinforcement piston 86 the ends distal of the actuator bars 91a and 91b, of the probe actuator section (Figure 16), are firmly attached within the clamp 80 to move the retraction assembly back and forth. The hydraulic block 82, described in more detail with respect to Figure 12, contains hydraulic valves for controlled retraction of the cam anchors in the event of an interruption of the electrical power supply. An arming piston 88, which extends from the section of the arming piston of the retraction assembly, is initially pushed inward by the forward movement of the retraction assembly, to generate hydraulic pressure in order to extend the cam anchors, such as described in more detail below with respect to Figures 9 and 12. Figure 9 shows the retraction assembly 76 with its cam anchors in retracted position and the reinforcing piston 88 extended. When the actuator of the probe initially moves the retraction assembly forward, until the end of its stroke, the piston 88 comes into contact with the wall of the lower bulkhead 89 of the probe (Figure 6), and is pushed into the assembly of the probe. retraction, forcing the hydraulic fluid out of the arming cavity 90. The cavity 90 has the outer end sealed with an O-ring 92 located around the axis of the piston 88, which has an enlarged guide portion 94 that slides along the arc. ° of the hole of. the cavity 90. A compression spring 96 forces the piston to exit outwardly 88. The hydraulic fluid displaced from the arming cavity 90 flows along the hydraulic pipe (not shown) located within the retraction assembly, through the a one-way check valve 98, to the annular cavity 100 about the retraction piston 102, forcing the piston 102 to move to the left, to the position shown in Figure 10, compressing the retention spring 104. Simultaneously, the Hydraulic fluid, displaced from the cavity 106 by the movement of the piston 102, flows, through the rod of the actuator 91b, into the cavity of the compensating piston 108, in the section of the compensator of the probe (Figure 15). Two twin cam support tracks 110, attached to the distal end of the piston 102, are dragged to the left when the retraction piston retracts. The cam members 60a and 60b (only the members 60a are visible in Figures 9 and 10) are attached to the rails 110 through bearings 112, defining pivot points of the cam anchors 114. In their retracted position, as shown in Figure 9, each cam member is clamped against a bolt 116 and a roller 118 by a related tension spring 120, which extends between the cam member and the housing of the retraction assembly 122, and by residual compression in the spring 104. One end of each spring 120 is attached to its corresponding cam member by a bolt 124. When the cam support rails 110 are moved to the left, the springs 120 force their corresponding cam members to move outwards, to their extended positions, as shown in Figure 10. When the rails 110 are moved back to the right (as shown in Figure 9), the turning points 114 are displaced to forward along the well with respect to the rollers 118. This relative movement - helps retract the cam members and ensures that the cable tension is applied to the cam members through the rollers 118 instead of the bearings 112. As can be seen in Figures 9 and 10, each cam member 60a and 60b, (not shown) has external and external portions, connected by threaded fasteners 125 so that they can be released and their outer portions (which have surfaces of arched cams 62) can be replaced in the field. Also, external portions of cam members of various sizes are provided, as shown in Figures 17A and 17C, which can be used with different tube diameters. Also, in some cases, the outer portions of the cam members of a cam anchor 58 (Figure 8) are of one size (eg in Figure 17A), while the outer portions of the cam members of the Another cam anchor is of another size (eg in Figure 17C), in order to accommodate a wide range of borehole diameters in a single well. Figure 11 presents, in a way, a better perspective of the structure of the anchor section 84 of the retraction assembly. The anchor section housing 122 has twin parallel side rails 126, each of which defines an internal groove 128 along which cams 110 support rails slide. The function of the hydraulic block 82 is best described Referring to Figure 12. Repeating said, the hydraulic fluid initially displaced from the arming cavity 90 flows through the check valve 98 to the annular cavity 100 around the retraction piston 102, forcing the piston 102 to move towards the left. Simultaneously, the fluid in the cavity 106 flows out of the retainer assembly into the cavity of a compensating piston 108 in the section of the compensator of the probe. Because the pressure of the cavity 100 is greater than that of the cavity 106, backflow is prevented through the check valve 128. The hydraulic block contains a normally open solenoid valve 130 that remains closed during normal operation of the valve. the probe maintaining an electrical voltage through the winding of a solenoid 132. In the event of an interruption of the electrical power supply, with the retraction assembly in a position where the arming piston can be fully extended (i.e., away from the bulkhead) lower of the probe), the retraction spring 104 forces the retraction piston 102 to move to the right, retracting the cam anchors. The fluid displaced from the cavity 100 flows, through the solenoid valve 130 and a check valve 134, into the arming cavity 90 as the arming spring 96 (Figure 9) forces the arming piston 88 to move. outside.

If the arming piston 88 is prevented from fully extending, as when the retraction assembly is in the fully forward position within the probe, excess fluid from the cavity 100 flows through the solenoid valve 130 and a check valve 136, to the cavity of the compensator 108. Then, when the arming piston is unblocked, it automatically extends, due to the internal hydraulic pressures, to passively readjust the arming system. Referring to Figures 13 and 14, the clamp of the retraction assembly 80 provides a firm connection to the bars of the probe actuator. The distal ends of the bars (not shown) are inserted into the holes 138a and 138b, where they are sealed by seals 140. A quick-connect hydraulic coupling 142 in the orifice 138b allows the rods to be disconnected from the hydraulic block 82 without need of draining the hydraulic cavities of the retraction assembly. A central block 144 of the clamp is fastened with a bolt 146 to the surface of the hydraulic block, and side plates 148 are installed from opposite sides of the central block to hold the actuator rods in position with soft clamp pads 150. The structure of the clamp 80 allows to disconnect the retraction assembly from the rest of the conveyor without dismantling the rest of the probe. The connection point of the actuator bars with the retraction assembly is provided with a fill and purge plug 152. The remainder of the conveyor 52 will be described with reference to Figures 15 and 16. Starting at the upper end of the probe (in the upper part of Figure 15), the upper front part 64 provides a dry electrical connection with later portions of the chain and instrument cable. At the upper end of the compensator section 66, an upper bulkhead for oil or air 154 provides an oil tight seal around the electrical conductors, which extend the entire length of the probe. Adjacent sections of the probe are coupled with split threaded rings 155, with electrical connections between adjacent sections made with bayonet-type connectors. The compensator section 66 also contains an annular compensation piston 156 which is attached to the end of the compression spring 158 and has seals to seal it against the surfaces of the compensator tube 160 and housing 162. A compensator cavity is defined on the piston 156. annular 108 communicating, by means of fluid, with the lower portions of the probe and with the retraction assembly through openings 164 and the internal bore of the shaft 160. The annular cavity 166 under the piston 156 is exposed to the orifice of the well through the side opening 168. A flexible stop 170 at the lower end of the cavity 166 prevents the piston 156 from striking the end of the cavity and ensures that the piston remains sealed against the inner surface of the housing bore. / The section of the probe actuator 68 will now be described in more detail. At the upper end of the actuator section, the electrical connector assembly 172 allows the actuator and compensator sections to be easily disconnected, and also allows hydraulic fluid to flow between these sections. The connector 172 also provides an electrical connection between the cable and the lower electrical systems, including the conductors that supply electrical power to the motor assembly 174. The motor assembly includes a brushless DC motor, driven by pulse widths that modulate a DC voltage of about 800 volts, and a planetary gear train that allows a speed reduction of 10: 1. The set has a diameter of approximately two inches (5 cm), a length of three inches (7.5 cm) and develops a horse power. The motor assembly has been installed adapting it to the housing of the actuator section, and the slot of its output shaft has been fitted to a cardan joint coupling 176, with its other side joined to a shaft with ball screw 178. The shaft with ball screw 178 is installed inside the housing of the actuator section, on a set of upper bearings 180 and a set of lower bearings 182. On the axis of the ball screw is installed a spherical nut 184 which it moves linearly along the primary axis of the instrument chain due to the rotation of the motor assembly 174.

Attached to the spherical nut is an upper rod support 186 that supports the upper ends of the actuator rods 91a and 91b. The linear displacement of the spherical nut 184 displaces the bars 91a and 91b along the axis of the instrument, thus moving the retraction assembly. Both rods 91a and 91b are hollow, and the bore of bar 91b provides a passage for hydraulic flow between the retraction assembly and the rest of the probe. Along the sealed hole of the bar 91a extends a single conductor (not shown) to provide electrical communication with the solenoid valve 130 (Figure 9). This conductor passes through coiled tubing (not shown) around the axis of the ball screw, between the ball nut 184 and the bearing assembly 180, to protect the driver as the distance between the ball nut and the bearings changes . The lower end of the actuator section contains a set of electrical connectors 188 for establishing electrical communication with the rail section 70. The upper end of the section 70 contains sliding seals 190 to create a seal against the rods 91a and 91b. Piping (not shown) between the upper and lower ends of the rail section carries electrical conductors and hydraulic fluid along the side rails 192. An oval slot 194, cut into the interior of each rail, receives tabs 196 (FIG. Figure 7) on each side of the arm piston section of the retraction assembly, to guide the retraction assembly along the rails. The lower front section 72 of the probe 52 contains another oil or air bulkhead 154 and provides a connection to the lower portions of the instrument chain. Referring to Figures 17A-17C, the outer portions of the cam members 198a and 198b are two examples of external portions of camshafts of different size suitable for wells with different diameters. As can be seen in Figure 17B, the external portions of the cam members are relatively narrow, and have wide and flat sides. Embedded in the distal edge of some cam members is a row of carbide-tipped 200 inserts to be fixed to the steel tubing walls. Referring to Figure 18, the electronic cartridge 54 allows controlling the two conveyor probes 52 of Figure 5 at the bottom of the well, Note that Figure 18 illustrates, by means of a diagram, the function of the electronic cartridge. the technique will understand that physical representations contain, in some cases, multiple components that, combined, perform the function illustrated by any of the elements shown in Figure 18. For example, a current physical representation of the cartridge contains no less than five microprocessors for control various aspects of the function of the instrument chain.

The signals and control data are superimposed on the high DC voltage of the monocable 18, which goes from the surface of the well to the instrument, by means of known telemetry techniques that produce a data transmission rate of between 13K and 26K symbols per second. . The cable power 18 is conditioned by filters 202 to power the actuator motors, and is reduced to lower voltages in the power source 204 to power the electronics. One or more on-board microprocessor controllers 206 control downhole functions, and electronic telemetry systems 208 are provided to generate and decode data signals from cable 18, and to separate the high voltage power from the superposition of telemetry with sufficient isolation to avoid corruption of telemetry signals. The nominal voltage of the cable in the instrument chain is about 600 volts DC during traction, but it fluctuates as the controller varies the parameters of the motor to maintain a reasonably constant traction speed, with feedback from the gear reducers. 174 engines Onboard sensors 210 are included to monitor system parameters for safety reasons and other functions. For example, some thermocouples monitor the temperatures of the electric heat sink and a strain gauge monitors the cable tension, to automatically retract the cam anchors and stop the actuator motors if undesirable conditions are detected. On the other hand, the engine speed, voltage and current can be monitored to calculate the torque of the motor. The motor driver 212 contains power transistors, pulse-modulated in duration, to power the three coils of each motor, and it is preferred that it be physically separated from the electronic telemetry system by a distance sufficient to reduce the signal noise.

In some cases, the electronic cartridge 54 is adjusted to be interconnected with an individual depth-of-well logging probe (such as the logging probe of Figure 5). In some cases, the sensor or diagnostic sensors, such as the CCL 214 sensor, are incorporated into the electronic cartridge itself, so that an individual logging probe is not needed. Of course, the electronic cartridge can be easily equipped to do both simultaneously. The electronic cartridge 54 also provides outputs (not shown) of filtered and unfiltered cable voltage that can be used by other instruments in the bottom of the chain. A computer located at the top of the well (not shown) provides an interface for the user. In some, the surface computer is also adapted to monitor the cable tension and current, and to deactivate the system if undesirable conditions are detected. A null stream, for example, may indicate an open wire. During use, the instrument chain should not be transported along the wellbore to such a large distance that, when retracting the cable, the friction between the cable and the surface of the well will develop a greater load than the cable can to resist. While the foregoing physical representations have been described with respect to the transport of a logging probe (which may or may not be incorporated in the electronic cartridge previously described), it should be understood that the transport system of the invention is equally suitable for transporting other types of instruments for the bottom of a well along a deviated well. For example, along these wells it is also possible to transport drilling cannons and other well completion instruments using the apparatus and method described previously. The above description of the preferred and alternative physical systems of the present invention has been presented for illustrative and descriptive purposes. It is not intended to cover all aspects or limit the invention to the precise form disclosed. Of course, those skilled in the art will discover many modifications and variations. The physical representations were chosen and described to better explain the principles of the invention and their practical application, thus enabling others skilled in the art to understand the invention for various physical representations and with various modifications as appropriate to the particular employment contemplated. Our intention is to define the scope of the invention with the attached clauses and equivalents.

Claims (23)

RE I V I ND I C A C I O N S

1. - An apparatus for transporting an instrument along a non-vertical well, said apparatus comprising the following: an elongate housing adapted to be connected to an instrument to be transported; a cam anchor adjusted to extend laterally from the housing and joined by a pivot to the housing at a displaceable pivot point; and an actuator operatively connected to the housing and designed to linearly displace the pivot point of the cam anchor along the housing; the cam anchor which has an arched cam surface to be coupled by the displacement to an inner surface of the well when the pivot point of the cam anchor is displaced in an initial direction and to be fixed on an inner surface of the well when the point The rotation of the cam anchor is displaced in a second direction, in order to transport the instrument along the well.

2. The apparatus of claim 1 comprising the following: the first and second said cam anchors joined to the housing at their respective pivot points spaced along the housing, the surfaces of the arches of the cams of the cam anchors aligned in a common direction, and the first and second of said actuators designed to separately displace the pivot points of the first and second cam anchors respectively, to transport the instrument along the well.

3. The apparatus of claim 1, wherein the cam anchor is adapted to rotate, around its pivot point, to a retracted position with the arcuate surface of its cams decoupled from the inner surface of the well.

4. The apparatus of claim 3, further comprising a spring adjusted to deflect the cam anchor to its retracted position.

5. The apparatus of claim 1, wherein the cam anchor comprises a pair of anchor members, oriented in the opposite direction, joined by a pivot to the housing at a common pivot point and adjusted to simultaneously engage opposite portions of the anchor. inner surface of the well.

6. The apparatus of claim 5, wherein both members of the anchor are adjusted to fix, around their common pivot point, to retracted positions, with the arched surfaces of their cams decoupled from the inner surface of the well, the apparatus comprising , also, a spring adjusted to deflect both members of the anchor to their retracted positions.

7. - The apparatus of claim 1, wherein the cam anchor has a plurality of projections extending from the arcuate surface of its cams to be fixed to the inner surface of the well.

8. The apparatus of claim 1, wherein the inner surface of the well consists of earth.

9. The apparatus of claim 1, wherein the inner surface of the well consists of the well tubing.

10. The apparatus of claim 1, wherein the transported instrument contains the following: a logging sensor that responds to a characteristic of the bottom of the well; and electronic systems adapted to activate the actuator.

11. The apparatus of claim 3, set to automatically retract the cam anchors from their retracted position when the power supply is interrupted.

12. The apparatus of claim 11, wherein the housing defines a slot; and wherein the apparatus includes: a retraction assembly comprising the cam anchor and an armed piston, and wherein the retraction assembly can be linearly displaced along the slot of the housing by the actuator between the front and rear positions, and where the arming piston extends from the retraction assembly and is adjusted to engage a surface of the housing, at one end of the slot, and to be compressed by the housing when the retraction assembly is moved to its front position, thereby forcing to the cam anchor to move to its extended position.

13. The apparatus of claim 12, wherein the retraction assembly includes the following: a retraction housing; a retraction piston, fitted within a hole of the housing of the retraction assembly and connected to the pivot point of the cam anchor, the retraction piston being communicated, by hydraulic means, to the arming piston and being adjusted to be displaced within of the housing bore to move the pivot point when the arming piston is compressed; and a tension spring, connected to the housing of the retraction assembly and the cam anchor and adjusted to force the cam anchor to move to its extended position when the arming piston is compressed.

14. The apparatus of claim 13, wherein the retraction assembly includes the following: a first one-way check valve, adjusted to pass a hydraulic flow, from the arming piston to the retraction piston, when the piston armed is compressed; a normally open solenoid valve, adjusted to pass a hydraulic flow, from the retraction piston to the arming piston, in the absence of electrical voltage in the solenoid; and a spring adjusted to deflect the retraction piston to a position that allows the cams to be retracted.

15. The apparatus of claim 14, further defining a compensation cavity, communicated by hydraulic means with the retraction piston and adjusted to receive hydraulic fluid from the retraction assembly when the solenoid valve is opened and the piston is blocked. of armed so that it does not extend completely.

16. A method for transporting an instrument to a predetermined position along a non-vertical well, the method comprising the following steps: (a) connecting the apparatus of claim 1 to an instrument to be transported; (b) lowering the instrument and the apparatus into a non-vertical well (c) activating the actuator to move the anchor pivot point in an initial direction in order to slide the surface of the cam anchor along the an inner surface of the well (d) activating the actuator so that it displaces the pivot point of the cam anchor in a second direction to be fixed to the inner surface of the well and transporting the instrument along the well; and (e) repeating steps (c) and (d) until the instrument is transported to the predetermined position.

17. The method of claim 16, wherein the apparatus has the following: the first and second said cam anchors attached to the housing of respective pivot points spaced along the housing, the arched surfaces of the cams being cam anchors aligned in a common direction; and the first and second of said actuators designed to move separately the turning points of the first and second cam anchors respectively, in order to transport the instrument along the well.

18. - The method of claim 17, steps (c) and (d), which comprises the following: i) activating both actuators to move the pivot points of both cam anchors in the second direction in order to couple the cam anchors against the internal surface of the well; and ii) activating each actuator sequentially to sequentially displace the pivot points of the cam anchors in the initial direction in order to transport the instrument along the well.

19. - The method of claim 18, wherein step 1) comprises activating an actuator to move the pivot point of a cam anchor in the initial direction, simultaneously activating the other actuator to displace the pivot point of the other cam anchor in the second direction.

20. The method of claim 17, comprising the following: between steps (b) and (c), activate both actuators to move the pivot points of the cam anchors in the second direction to couple the cam anchors against the inner surface of the well; and, while maintaining a cam anchor coupled to the inner surface of the well, perform steps (c) and (d), comprising steps (c) and (d) activating the actuator related to the other cam anchor for Alternate the pivot point of the other cam anchor in the first and second directions in order to transport the instrument along the well.

21. The method of claim 20, wherein the cam anchor in question is deflected towards the inner surface of the well by a spring.

22. - The method of claim 16, wherein the transported instrument contains a sensor of a log that corresponds to a characteristic of the bottom of the well.

23. - The method of claim 22, wherein the transported instrument also contains electronic systems adjusted to activate the actuator.