MXPA00011519A - Generating commands for a downhole tool - Google Patents

Abstract

A system is used with a well that has a downhole tool which is responsive to a stimulus. The system includes a fluid circulation path that is connected to circulate a fluid and a flow restrictor that is connected in the fluid circulation path and located at the surface of the well. A controller causes the flow restrictor to selectively alter flow of the fluid in the circulation path, and a link is coupled to the circulation path to furnish the stimulus to the downhole tool in response to the alteration of flow by the flow restrictor.

Description

GENERATION OF INSTRUCTIONS FOR A TOOL LOCATED IN THE DRILL FUND BACKGROUND The invention relates to the generation of instructions for a tool located at the bottom of the hole. With reference to Figure 1, for purposes of measuring the characteristics (e.g., formation pressure) of an underground formation 31, it is possible to insert a tubular string 10 into a hole extending in formation 31. To test a particular region or zone 33 of the formation 31, the string 10 may include a perforating gun 30 which is used to penetrate a casing 12 and form fractures 29 in the formation 31. To seal with mud the area 33 of the surface of the well , the string 10 usually includes a packing seal 26 that forms a seal between the outside of the string 10 and the inner surface of the casing 12. Below the packing plug 26, a recorder 11 of the string 10 takes the measurements of the formation 31. The tool 21 usually has valves to regulate the flow of fluid in and out of a central passage of the string 10. An in-line ball valve 22 is used to regulate the The flow of the fluid from the well of the formation 31 through the central passage of the test string 10. On the packing plug 26, a circulation valve 20 is used to regulate the hydraulic communication between a ring 16 surrounding the string 10 and the central passage of the string 10. 5 The valve of the 22 and the circulation valve 20 can be regulated by means of instructions (for example, "open valve" or "close valves") that are sent to the bottom of the perforation. Each instruction is encoded in a predetermined pressure pulse signal 34 (Figure 2) which is transmitted to the bottom of the bore to the tool 21 through the hydrostatic fluid present in the ring 16. A detector 25 of the tool 21 receives the pressure pulses 34, and the instruction is extracted. The hydraulic electronics of the string 10 then operates the valves 20 and 22 to execute the instruction. For purposes of generating the pressure pulses 34, an opening 18 in the casing 12 extends to a manually operated pump (not shown). The pump is switched on and off selectively by a The operator for coding the instruction in the pressure pulses 34. A duration T0 (for example, one minute) of the pulse 34, a pressure p0 (for example, 250 psi) of the pulse 34 in succession form the signal that uniquely identifies the instruction . 25 jjMßto ^^^? ^ fctóSá ^^^^^^^^^^^^^ g ^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^ j ^^^^^^^ g ^^^ * ^ ^^^^ Compendium In a modality, a system is used with a well that has a tool located at the bottom of the perforation that is sensitive to a stimulus. The system includes a hydraulic circulation path that is connected to circulate a fluid and a fluid choke that is connected in the hydraulic circulation path and located on the surface of the well. A controller causes the fluid choke to selectively modify the flow of fluid in the flow path, and a link is coupled to the flow path to supply the stimulus to the head located at the bottom of the bore in response to modification of the flow. Flow through the hydraulic choke. The advantages and other features of the invention will be apparent from the following description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of a test string in a well being under review. Figure 2 is a waveform illustrating an instruction of the pressure pulses for a tool of the test string of Figure 1. Figures 3a and 4-9 are schematic views of a £., 4 Jt j string that includes multiple valves and seals. Figures 3b and 3c are shapes waveforms illustrating pressure pulses transmitted to the tools of the test string. Figure 10 is a block diagram of a hydraulic system for regulating the valves of the tools. Figure 11 is a block diagram of the electronics for regulating the valves of the tools. Figure 12 is a sectional view of the test string illustrating the operation of the ball valve. Figure 13 is a sectional view of a test string illustrating the operation of the circulation valve. Figures 14 and 15 are flow diagrams illustrating the operation of the electronics of the tools in the test string. Figure 16 is a schematic diagram illustrating another test string in a well being tested. Figures 17 and 18 are flow diagrams illustrating the operation of the electronics of the test string tools. Figure 19 is a cross-sectional view of a multilateral well. Figures 20 and 21 are flowcharts that illustrate the operation of the valve units in Figure itíkiéhá. 19. Figure 22 is a block diagram of a system for generating pressure pulse instructions. Figure 23 is a waveform illustrating an instruction of the pressure pulses generated by the system of Figure 22. Figures 24 and 25 are schematic diagrams of the wells. Figure 26 is a schematic diagram of a string including piercing guns.

Detailed description As shown in Figures 3a-3c, a regular test string 40 having two online test tools 50 and 70 is located within a well. To send an instruction (eg "open valves" or "close valve") towards the bottom of the bore to the upper tool 50, a sludge pump 39 is used to encode the instruction in a series of pressure pulses 120 ( that is, an instructional stimulus) which is applied to the hydrostatic fluid present in an upper ring 43. The upper tool 50 has a detector 54 in contact with the hydrostatic fluid in the upper ring 43. The upper tool 50 uses the detector 54 for identify the signal of the pressure pulses 120 and, of ^^ L ^ j ^ fcyg¡¡ ^ ¡= ¿^^^^^ ^ ^^^^; ^^^^^ - * ¡j¿ * ¿^ ^ ^ ^ ^^^^ this way, extract the coded instruction . In response to the appropriate instructions, the upper tool 5 is constructed to drive an on-line ball valve 53 and / or a circulation valve 51. The upper ring 43 is the annular space on a packing seal 56 that forms a seal between the exterior of the upper tool 50 and the interior of the casing 44. Because the lower tool 70 is located below the packing plug 56, the fluid in the top ring 43 can not be used as a means for sending directly pressure pulses (and thus commands) to the lower tool 70. However, because a central passage of the test string 40 extends through the obturator 56, this central passage can be used as a conduit for the passage of the instructions to the lower tool 70. As described below, the instructions are sent to the lower tool 70 using a ball valve 53 of the tool The upper tool 50 is formed to form pressure pulses 122 in the well fluid (eg, oil, gas, water or a mixture of these fluids) present in a lower ring 42 below the packing plug 56. The lower tool 70 has a detector 74 in contact with the fluid in the lower ring 42. The lower tool 70 uses the detector 74 to receive the pulses 122 and, in this way, extract the instructions sent by the upper tool 50. Thus, the instructions are sent to the lower tool 70 by the upper tool 50. More specifically, to send an instruction to the lower tool 70, the mud pump 39 it first creates pressure pulses 120 in the fluid in the upper ring 43. The pressure pulses can be negative or positive changes in the pressure (relative to a base pressure level), and the pressure pulses 120 form a signal indicating an instruction for the lower tool 70. In this way, the upper tool 50 receives pressure pulses 120, decodes the instruction of the pulses 120, and selectively opens and closes the ball valve 53 to send the instruction to the lower tool 70 to through pressure pulses 122. The pressure pulses 122 is applied to a fluid column of the well existing in the central passage of the string 40 where the The string 40 extends through the packing plug 56. The perforated bottom tubes 90 of the string 40 establish hydraulic communication between the central passage of the string 40, the ring 43, a ring 42 and a ring 41. For example, the bottom perforated tubes 90 may be located above and below a perforating gun 57 (of string 40) which is located in ring 42. Thus, the tubes of the ^ ¡^ * Lfe «jai ^^^ S ^^^^^» ^^^^^^^^^^^^^^^^^^^ bottom 90 establish hydraulic communication between the passage central of the string 40 and the ring 42. Thus, due to this arrangement, the pressure pulses 122 that are formed by the upper tool 50 propagate to the lower ring 42. As a result, the lower tool 70 uses the detector 74 for identify the unique signal of the impulses 122 and thus extract the instruction,. After extracting the instruction, the lower tool 70 executes the instruction. The above described arrangement advantages may include one or more of the following: the tools below the packing plug can be regulated without extending pressurized hydraulic lines or wires through the packing plug; it is possible that no additional electronics is required; and it may be that no additional hydraulics are required. In addition to the detector 54 and the ball valve 53, the upper tool 50 may include a circulation valve 51 and an electronic one configured to decode the signal from the pressure pulses 120 and to regulate the valves 53 and 51 accordingly. A recorder (not shown) may be located below the packing plug 56 to take characteristic measurements of the fluid in the lower ring 42. In some embodiments, the string 40 may include a perforated bottom tube 90 that is located above of a ball valve 72 of the lower tool 70. when controlled by the ball valve 72, the bottom tube 71 allows hydraulic communication between the lower ring 42 and a central passage of the string 40 extending through the obturator 76. The packing plug 76 forms a seal between the exterior of the lower tool 70 and the interior of the casing 44, thereby forming a test area 45 and a ring 41 below the packing plug 76. The lower tool 70 also electronics to decode the pressure pulses 122 and operate the ball valve 72 accordingly. Located below the packing plug 76 is a perforating gun 82 which may be between two perforated bottom tubes 90 which establish hydraulic communication between the central passage of the test string 40 (extending through the packing plug 76) and the ring 41, controlled by the ball valve 72. A recorder 80 can also be located below the packing plug 76 to take the measurements in the test area 45. As an example, the string 40 can be inserted into the well to be drilled and measure the characteristics of a formation 32 using a process, as described below. The circulation valve 51 remains closed except when it is necessary to establish hydraulic communication between the upper ring 42 and the central passage of the string 40. To begin the process, as shown in Figure 3A, the test string 40 is inserted into the well with both ball valves 53 and 72 open. Next, as shown in Figure 4, pressure is applied through the tubular test string 40 to detonate the piercing gun 82. When detonated, the gun loads 82 form lateral fractures 100 in the formation 32 and the liner pipe 44 below packing plug 76. As shown in Figure 5, once perforations 100 are formed, sludge pump 39 is used to send an instruction to upper tool 50 to close the ball valve 53. Tests are then carried out in zone 45 to measure the characteristics of perforations 100. After the tests are completed, there is a column of fluid from the well in the central passage of the test string 40 below the valve. ball 53. As seen in Figure 6, once the tests of zone 45 are completed, a process is performed to seal area 45 with sludge. To accomplish this, sludge pump 39 instructs the upper tool 50 to open and close the ball valve 53 in such a manner to generate pulses of ^ iia ^ j, .AA ... j.j .. pressure in the column of the well fluid below the ball valve 53. These pressure pulses have a predetermined signal indicative of an instruction for the lower tool 70 to close the ball valve 72. When the lower tool 70 recognizes the signal ( through the detector 74), the lower tool 70 closes the ball valve 72 and closes the area 45 with mud. As shown in Figure 7, once the ball valve 72 has been closed, the piercing gun 59 is closed. it detonates to form another series of perforations 130 in another formation 33. Because the ball valve 53 is open, the well fluid flows up through the perforated bottom tube 57 and passes the packing plug 56. The formation 33 then it is tested using the upper tool 50. As shown in Figure 8, once the tests of the formation 33 are completed, the mud pump 39 then sends instructions to the upper tool 50 to open and close the ball valve 53 in such a manner as to generate pressure pulses in the column of the well fluid below the ball valve 53. These pressure pulses have a predetermined signal indicative of an instruction for the lower tool 70 to open the ball valve 72. When the lower tool 70 recognizes this signal, the lower tool 70 opens the kt it? jíj ^^ j ^ rf ^^ í? jjjßis ^^^ ß ^^^^^^ i ^? ^^ ball valve 72, and formations 32 and 33 are tested together. The test procedure described above requires that there is a column of fluid from the well below the ball valve 53. Sufficient pressure (usually exerted by the fluid in formations 32 and 33) must also be exerted on the column so that the opening and closing of the valve 53 produces pressure variations (Figure 3B) large enough to detect the detector 74. If the formations 32 and 33 do not exert sufficient pressure, the circulation valve 51 can be opened and another fluid, as can be light (eg nitrogen), is injected into the central passage of the string 40 above the ball valve 53. The gas displaces the fluid from the well above the valve 53 to reduce the hydrostatic pressure above the ball valve 53 and create a pressure difference necessary to generate the pressure impulses 122. Otherwise, a fluid, such as the "kill" fluid of the formation, can be injected into the country The central axle of the string 40 and the lower ring 42 so that the pump 39 can be used to send the instructions to the tool 70. Each of the tools 50 and 70 uses hydraulic 249 (Figure 10) and electronic 250 (Figure 11). ) to operate the valves. As shown in Figure LO, each valve ^^^^^ SJ Ftí? G &^^^^ ga ^ w »^^^^^^^ uses a tubular element operated in hydraulic form 156 which through its longitudinal movement opens and closes one of the valves. The element 156 is slidably mounted within a tubular housing 151 of the test string 40. The element 156 includes a tubular mandrel 154 having a central passage 153 coaxial with a central passage 150 of the housing 151. The element 156 also has a annular piston 162 extending radially from the outside of mandrel 154. Piston 162 resides within a chamber 168 formed in tubular housing 151. Element 156 is urged downwardly by using an opening 155 in housing 151 to change the applied force to an upper face 164 of the piston 162. Through the opening 155, the face 164 is subjected to hydraulic pressure (a pressure greater than atmospheric pressure) or to an atmospheric pressure. A compressed spiral spring 160 in contact with a lower face 165 of the piston 162 exerts upward forces on the piston 162. When the upper face 164 is subjected to atmospheric pressure, the spring 160 pushes the element 156 upwards. When the upper face 164 is subjected to hydrostatic pressure, the piston 162 is pushed downwards. The pressures in the upper face 164 are established by connecting the opening 155 with a hydrostatic chamber 180 (supplying hydrostatic pressure) or a chamber discharge, atmospheric 182 (supplying atmospheric pressure). 4 solenoid valves 172-178 and two pilot valves 204 and 220 are used to selectively establish hydraulic communication between the chambers 180 and 182 and the opening 1555. The pilot valve 204 regulates the hydraulic communication between the hydrostatic chamber 180 and the opening 155, and the pilot valve 220 regulates the hydraulic communication between the atmospheric discharge chamber 182 and the opening 155. The 10 pilot valves 204 and 220 are operated by the application of hydrostatic and atmospheric pressure to regulate the openings 202 (pilot valve 204) and 224 (pilot valve 220). When hydrostatic pressure is applied to regulate the opening the valve closes, when atmospheric pressure is applied to the control opening, the valve opens. The solenoid valve 176 regulates the hydraulic communication between the hydrostatic chamber 180 and the control aperture 202. When the solenoid valve 176 is energized, hydraulic communication is established between the hydrostatic chamber 180 and the control aperture 202, thereby closing the pilot valve 204. The solenoid valve 172 regulates the hydraulic communication between the atmospheric discharge chamber 182 and the control aperture 202. When the solenoid valve 172 is energized, communication is established ^^^ tó ^^ & ^^^^ g & g ^^^^^^^^^^^^^^ i ^^^^^^^^^^^^^^^^^^ ^^^^^^^ a ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the control opening 202, thereby opening the pilot valve 204. The solenoid valve 174 regulates the hydraulic communication between the hydrostatic chamber 180 and the control opening 224. When the solenoid valve 174 is energized, hydraulic communication is established between the chamber hydrostatics 180 and control aperture 224, thereby closing the pilot valve 220. Solenoid valve 178 regulates hydraulic communication between the atmospheric discharge chamber 182 and the control aperture 224. When the solenoid valve 178 is energized, it is established hydraulic communication between the atmospheric discharge chamber 182 and the control aperture 224, thereby opening the pilot valve 220. In this way, to force the movement of the element 156 downwards, (which opens the valve) the electronics 250 of the tool energizes the solenoid valves 172 and 174. To force the movement of the element 156 upwards (which closes the valve), the electronics 250 energizes the solenoid valves 176 and 178. The hydraulics of the tool furthermore is described in US Pat. No. 4, 915,168, entitled "Multiple Well Tool Control Systems in a Well Test System with Multiple Valves", which is incorporated herein by reference. As shown in Figure 11.1a to electronics 250 for each of the tools 50 and 70 includes a controller 254 which, via an input interface 266, can monitor a ring pressure detector (e.g., detector 54 or 74). Based on the instruction pressure pulses received by them, the controlled 254 uses solenoid drivers 252 to operate the series of solenoid-operated valves 172a-178a for the ball valve 10 and a series of solenoid-operated valves 172b- 178b for the circulation valve. The controller 254 executes the programs stored in a memory 260. The memory 260 may be a non-volatile memory, such as a read-only memory (ROM), a programmable read-only, electrically erasable memory (EEPROM), a memory programmable read only (PROM). The memory 260 may be a volatile memory, such as a random access memory (RAM). The battery 264 (regulated by a power regulator 262) supplies power to the controller 254 and the other electronic circuits of the tool. As seen in Figure 12, each of the ball valves 53 and 72 includes a spherical ball member 269 having a passage 274. An arm 275 attached to the movable member 156 engages an eccentric connecting tab 270. ^ *? fa ^^^^^ M ^^^^^^^^? ^^^^^^^^^^^^^^^^ j ^^^^^^^^^^ ^^^^^^^^^ »j ^^^^^^^^^ - ^^^^^^^^ j ^^^^^^^ ^^^^^^ that joins through slots radial 172 to element 269. By moving element 156 up and down, the ball element rotates on an axis perpendicular to the coaxial axis of central passage 150, and passage 274 moves in and out of central passage 150 to open and close the ball valve, respectively. As shown in Figure 13, for the circulation valve 51, the housing 151 has a radial opening 304 extending from the outside of the tool, through the housing 151, and toward the central passage 150. A shutter 302 located in a recess 301 on the outside of the element 156 is used to open and close the circulation opening 304. By moving the member 156 up and down, the circulation valve 51 opens and closes, respectively. As shown in Fig. 14, the controller 254 of the upper tool 50 executes a routine known as AN_CNTRL to decode the instructions sent by the mud pump 39 and drive the ball valve 53 accordingly. In routine AN_CNTRL, controller 254 monitors 350 pressure through detector 54. If controller 254 determines 352 that a pressure pulse has not been detected, then controller 254 returns to step 350. However, if it has been detected a pressure pulse, the controller 254 then decodes 354 the «Feat ^ ¿rjj instruction. If the controller 254 does not recognize the instruction 356, then the controller 254 returns to step 350. Otherwise, the controller 254 determines 358 if the instruction is for another tool located at the bottom of the bore (i.e., the lower tool 70). If not, then controller 254 operates 360 valves 51 and 53 to perform the instruction and returns to step 350. If controller 254 determines 358 that the instruction was for lower tool 70, then controller 258 act 362 the ball valve 53 to send the instruction down to the lower tool 70. As shown in Figure 15, a routine called TU_CNTRL, the controller 254 of the lower tool 70 performs a series of steps to decode the instructions sent by the upper tool 50. In the routine TU_CNTRL, the controller 254 first monitors 364 the pressure detector of the pipe 258. If the controller 254 determines 366 that it detects a pressure pulse, then the controller 254 decodes the 268 instruction. If the controller 254 recognizes 370 the instruction, the controller 254 drives 372 the flow valve 71 and the ball valve 72 of the lower tool 70 to perform the desired function. The controller 254 then returns to step 364. In another embodiment, the ball valve 53 is located in the _ ^ Hftyfl fflf ^ | fW¡tjj ^ surface of the well. The ball valve 53 is controlled by the electric wires extending to the ball valve 53 (instead of through the pressure pulses 120 transmitted through the upper ring 43). Other modalities include a test string with more than two tools located at the bottom of the hole. For example, as shown in Figure 16, in a test string 405, a tool 400 generates the instructions for three tools 401a-c located at the bottom of the tool bore 400. To select the correct tool 401a-c , the tool 400 generates the same instruction more than once. The number of times the tool 400 generates the instruction identifies the receiver of the instruction. For example, for tool 400 to transmit an instruction to tool 401c, only one instruction is sent by tool 400. For tool 401b, tool 400 sends two instructions, and for tool 401a, tool 400 sends three instructions . As shown in Figure 17, the above-described sequencing method for directing the tools 401a-c, the controller 254 in each of the tools 401a-c executes a routine called TU_CNTRL_MUL1. In the routine TU_CNTRL_MUL1, the controller 254 monitors the pressure detector in line 258. If the controller 254 determines 452 that a pressure pulse is detected, then the controller 254 decodes the instruction 454. If the controller 254 recognizes 456 the instruction, then the controller 254 increments 458 a parameter called TCOUNT (set equal to 0 in the restoration of the electronic circuits 250) which indicates the number of times the instruction has been detected. If the controller 254 determines 460 that the parameter TCOUNT indicates that the tool has been selected, then the controller 254 operates 462 the valves to perform the instruction and returns to step 450. If the instructions are for a tool located beyond the bottom of the perforation, then controller 254 determines 464 if the ball valve of the tool is closed (i.e., thereby indicating that the instruction did not reach the next tool at the bottom of the borehole). If not, the controller 254 returns to step 450. However, if the ball valve is closed, then the controller 254 and 401 drives the ball valve in a way to send the instruction to the bottom of the bore. As shown in Figure 18, in another embodiment, the tool 400 uses pressure pulses in the central passage of the test string 405 to send an address with the instruction. The address identifies only one of the tools at the bottom of bore 401a-c. In this mode, the controller 254 for each of the tools 401a-c executes a routine called TU_CNTRL_MUL2. The routine TU_CNTRL_MUL2 is identical to the routine TU_CNTRL_MUL1 with the exception that step 458 is replaced with step 478 in which the controller 254 decodes 478 the address sent by the tool 400. As illustrated in Figure 19, the control of the Devices at the bottom of the drilling as already described can extend beyond the test strings to the bottom of the drilling. In Figure 19, the principles apply to a real production environment. For example, a multilateral well 500 may have computer controlled valve units 508-512 that regulate the flow of the well fluid from side holes 502-506, respectively, to a backbone 501 of the well 500. Each of the valve units 508 -512 has the same electronic circuits 250 and hydraulic 249 as described above together with a ball valve for regulating the flow of fluid through the central passage of the valve unit. The flow of the well fluid through the trunk 501 is regulated by a valve unit 520, similar in design to the valve units 508-512. As shown in Figure 20, the controller 254 in each of the valve units 508-512 executes a routine called LAT CNTRL1. In the LAT routine CNTRL1, the controller 254 monitors 600 the pressure on the trunk 501. If the controller 254 detects a pressure pulse 602, then the controller 254 decodes the instruction 604. If the controller 254 then recognizes 260 the instruction being for the valve unit, the controller 254 drives 208 the ball valve of the valve unit to execute the instruction. As shown in Figure 21, the controller 254 for the valve unit 250 executes a routine called TRUNK_CNTRL. In the TRUNK_CNTRL routine the controller 254 monitors 620 the pressure on the trunk 501. If the controller 254 determines 622 that the pressure has fallen below a predetermined minimum threshold, then the controller 254 performs 624-634 a series of operations to increase the pressure on trunk 501. Controller 254 first determines 624 if valve 508 is open, and if not, controller 254 then drives 626 the ball valve of unit 520 to generate an instruction to open valve unit 508. the controller 254 then returns to step 620. If the valve unit 508 is open, then the controller 254 determines 628 if the valve unit 510 is open, and if not, the controller 254 drives 630 the ball valve of the valve unit 520 to generate an instruction or open the valve unit 510 and returns to step 620. If the valve unit 510 is open, then the controller 254 determines 632 if the valve unit 512 is open, and if so, the controller 254 drives 634 the ball valve of the unit 520 to generate an instruction to open the valve unit 512 and returns to step 620. If the controller 254 determines 636 that the pressure in the trunk 501 is greater than a predetermined maximum threshold, then the controller performs steps 638-648 to reduce the pressure in the trunk. Controller 254 first 10 determines 638 if valve unit 508 is closed, if not, controller 254 drives 640 the ball valve of valve unit 520 to send an instruction to close valve unit 508 and returns to step 620. If the controller 254 determines 642 that the valve unit 510 is closed, then the controller 254 drives 644 the ball valve of the unit 520 to send an instruction to close the valve unit 510 and returns to step 620. If the controller 254 determines 646 that valve unit 512 is closed, then controller 254 drives 648 ball valve 20 of valve unit 520 to send an instruction to close valve 512 and returns to step 620. In other embodiments, valve unit 520 is located on the surface of the well. The valve unit 520 is regulated by electrical cables connected to the valve unit 520. 25 Instead of using the sludge pump 39 to generate j ^^^^^ to ^^^ ¡? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^? ^^^^^ tg ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ j ^^^ ^^ a single instruction to instruct the upper tool 50 to generate an instruction for the lower tool 70, in an alternative mode, a series of instructions is sent by the mud pump 39 to directly control the opening and closing of the valve ball 53 in the instruction generation for the lower tool 70. With reference to Figures 22 and 23, the manually operated pump 39 can be replaced by an automated system 699 to transmit instructions to the bottom of the bore. The advantages of using an automated system for transmitting instructions to the bottom of the borehole may include one or more of the following: the instructions of the pressure pulses may be transmitted to the bottom of the bore using push button control; Pulse synchronization can be precisely controlled and pulse transmission can use an advanced coding scheme; more instructions can be transmitted in shorter times; it is possible to use pressure pulses that have a shorter duration; it can reduce operator error; and it is possible to control multiple tools at the bottom of the hole. In some embodiments, the automated system 699 includes a hydraulic pump 700 that circulates a fluid ^ - * ^ - * ^ -M * - > - * '- > ** »-. * ájJ ^ J tm ?. -. ^ »* > A ú > ** »m ~ > . . ~ ^. -. «~ J ... -. * ».. *»? »M. l ?, (eg, liquid sludge) inside and outside the holding tank 706 and establishes a constant metric flow rate for the system 699. A throttle, or hydraulic shutter 704, is located in a circulation path between the pump 700 and tank 706 and establishes a base pressure level P0 (100 psi) for system 699. Depending on the particular mode, a pressure P (Figure 23) may be exerted on the hydrostatic fluid in ring 43 or in the central passage of the string at the bottom of the perforation by a link, or conduit 705, which is diverted to the hydraulic fluid 707 that supplies the fluid to the system 699 to the hydraulic choke 704. To modulate the pressure P, the 699 system includes a choke , or hydraulic reducer 702, which is controlled by a 708 computer (e.g., a laptop) in a way to send instructions to the bottom of the bore by modifying the pressure from the pre base station Po which is established by the hydraulic reducer 704. In some embodiments, the hydraulic reducer 702 is connected in a fluid flow path between the outlet of the pump 700 and the inlet of the flow line 707. In some embodiments, the hydraulic pump 700; the hydraulic reducers 702 and 704; and tank 7606 are located on the upper surface of the well to establish fí &^; ^ ^^^ Mj ^^! ^ Í¡ [j * ^^^^^ & & amp; Jg) ^^^^^^ i ^^ a circulation path on the surface of the well. Also, in some embodiments, the hydraulic reducer 702 can be a tool similar in design to a measurement tool while drilling (MWD) that is located in the hydraulic circuit on the surface of the well and is electrically coupled to the computer 708. this mode, for the modalities where a MWD type tool is used, the portion of the tool that is configured to selectively alter the flow can be used to form at least a part (if not all, in some embodiments) of the hydraulic reducer 708. In some embodiments, the surface hydraulic circuit allows the formation of pressure pulses that are transmitted to the bottom of the borehole through a stationary fluid. For example, with reference to Figure 26, in a system 800. The pressure pulses may be transmitted to the bottom of the bore by a stationary fluid column which is located at the central passage of a string 802. In this mode, a control module 854 can respond to pressure pulses that can, for example, direct an initiator module 856 to fire its associated piercing gun 859. The control module 854 can communicate with the initiator modules 856 via a signal on an energy line 882. In other embodiments, a circulation valve module 804 of the string 802 may be open to allow fluid to circulate between the central passage of the string 802 and a ring surrounding the string 802. For these modes , the surface hydraulic circuit creates pressure impulses in the circulating fluid. Referring again to Figures 22 and 23, the computer 708 modulates the pressure drop through the hydraulic reducer 702 by selectively sealing, or throttling, the cross section of the flow path where the fluid passes through the choke 702. As a result , the pressure P is modulated. As shown, negative pulses are generated. However, positive impulses may otherwise be generated, as described below. When the computer 708 instructs the hydraulic reducer 702 to allow fluid flow to pass through the unobstructed reducer 702, the pressure P is approximately equal to the base pressure level P0, since no appreciable pressure drop occurs at through the reducer 702. To reduce the pressure P to a predetermined level Pi, the computer 708 instructs the hydraulic reducer 702 to limit the flow of the fluid which causes a pressure drop through the hydraulic reducer 702. Thus, the Instructions are formed by modulating the pressure in the hydrostatic fluid in ring 43 between the pressure levels P0 and Pi. Figure 23 shows an example of a transmission sequence 731 in which a signal 730 of the pressure pulses is transmitted. The computer 708 indicates the beginning of the sequence 731 by reducing the pressure P to the pressure level Pi to transmit a logical zero initial pulse 720. The computer 708 then modulates the pressure, as described above, to transmit negative pressure pulses 722 , 723 and 724 of the signal 730. The pressure pulses 722, 724 include logic pressure pulses 1 722 and 724 and a logic pressure pulse 723. The termination of the sequence 731 is indicated by a 0 pulse, logic 726 which has a longer duration than the other logical pulses 0 (for example, the pulse 723) of the sequence 731. In other embodiments, the conduit 705 may alternatively be derived in a flow line 709 which supplies fluid from the hydraulic pump 700 to the hydraulic reducer 702. As a result of this arrangement, the flow reducer 702 creates positive pressure pulses (instead of negative) in a manner similar to that described above. Thus, with reference to Figure 24, the automated system 799 can be used, as an example, in a well 750 to create pressure pulses in a ring 756 to control a valve of a test tool at the bottom of bore 752 ( part of a test string 754. As another example, in a well 760 (see Figure 25), the automated system 699 can be used to send instructions to the bottom of the bore through a central passage 765 of a 764 pipe instead of sending the instructions through a ring 766 surrounding the pipe 764. In this way, the automated system 699 can be used to modulate the hydraulic pressure in the pipe 765 to operate, for example, a drilling gun 762 in hydraulic communication with the fluid in line 764. Although the invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations of the It is proposed that the attached clauses cover all these modifications and variations that fall within the spirit and scope of the invention. , ^^^^^^^^^^^^^^^^ 6 ^^^^^^^^^^^^^^^^^^^^^^ - ^ tjA ^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ j ^ j ^^^ j ^^

Claims (9)

1. A system for use with a well having a tool at the bottom of the hole that is sensitive to a stimulus, the system consists of: a hydraulic circulation path located on the surface of the well and adapted to circulate a fluid, the way of circulation includes a hydraulic reducer; a controller adapted to cause the hydraulic reducer to selectively modify the flow of fluid in the circulation path; and a link coupled to the circulation path and adapted to supply the stimulus to the tool at the bottom of the bore in response to the modification of the flow by the hydraulic reducer. The system of claim 1, wherein the controller selectively modifies the fluid flow to vary a pressure in the fluid. The system of claim 1, wherein the stimulus consists of one or more pressure pulses transmitted through a fluid in the well, and wherein the bond consists of a connected conduit for conveying pressure on the fluid in the way of fluid circulation in the well. És ^^^^^? ^^^^ * ^^^^^. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1, where the controller consists of a computer. The system of claim 1, wherein the circulation path includes a holding tank configured to temporarily store the fluid. The system of claim 1, wherein the circulation path includes another hydraulic reducer to establish a hydraulic base pressure in the circulation path. The system of claim 1, wherein the circulation path further contains a hydraulic pump for circulating fluid through the circulation path at a constant volumetric flow rate. The system of claim 1, wherein the link is further adapted to supply the stimulus to a well ring. 9. The system of claim 8, wherein the tool at the bottom of the bore is adapted to respond to the stimulus in the ring. The system of claim 1, wherein the link is further adapted to supply the stimulus to a central passage of the pipe that is coupled with the tool. 11. The system of claim 10, wherein the tool is adapted to respond to the stimulus in the ^^ t ^^^ ßjJ ^ j ^ g ^^^^^ g ^^^^^^ j ^^^^ g ^^^^^^^^^^^^^^ feS ^ ^^? ^^ e ^^^ fc ^ central passage. The system of claim 1, wherein the link is further adapted to deliver the stimulus to the generally stationary column of fluid at the bottom of the bore. The system of claim 1, wherein the link is further adapted to supply the stimulus of the circulating fluid at the bottom of the bore. 14. A method for use with a well having a tool at the bottom of the perforation that is sensitive to a stimulus, the method consists in: creating a fluid in a superficial communication path; selectively modify the fluid flow; Supply the stimulus at the bottom of the hole to the tool in response to the modification. 15. The method of claim 14, wherein the act of modifying consists in varying a pressure in the fluid. The method of claim 14, wherein the stimulus consists of one or more pressure pulses transmitted through a fluid in the well, and wherein the supply consists of: transporting pressure in the fluid in the path of surface circulation to fluid in the well. 17. The method where modifying consists of: using a computer. 18. The method of claim 14, wherein the act of circulating includes temporarily storing the fluid. The method of claim 14, wherein the act of circulating includes establishing a base hydraulic pressure. The method of claim 14, wherein the act of circulating includes the use of a hydraulic pump to circulate the fluid at a constant volumetric rate.