Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/11—Perforators; Permeators
  • E21B43/116—Gun or shaped-charge perforators
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/11—Perforators; Permeators
  • E21B43/116—Gun or shaped-charge perforators
  • E21B43/117—Shaped-charge perforators
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/20—Flexible or articulated drilling pipes, e.g. flexible or articulated rods, pipes or cables
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/11—Perforators; Permeators
  • E21B43/119—Details, e.g. for locating perforating place or direction

Definitions

• This invention relates to the use of perforating guns for perforating multiple casings and the surrounding tight reservoir formations, e.g., in preparation for hydraulic fracturing of the formation in the absence of a drilling rig at the well.
• Tight gas formations such as Khuff carbonate, pre- huff sandstone and shale gas formations with high compressive strength require hydraulic fracturing procedures in order to open the reservoir formation and enhance the flow of gas to the well bore for production.
• a perforating gun is used to initiate formation breakdown by detonating high-performance deep-penetrating shaped charges that maximize perforation length and entry hole size to start the hydraulic fracturing or "hydrofracking", in order to enhance hydrocarbon production and optimize well flow.
• Existing methods and systems have not reliably produced deep penetrations into the surrounding formation when the region includes a completion with more than two casings and intermediate cement.
• a system and method for positioning a perforating gun in wellbore completions for performing multiple same location reservoir penetrations is disclosed in published application US 2014/0020896, the disclosure of which is incorporated herein by reference.
• the apparatus of this prior art system consists principally of the gun positioned below a latching tool that is attached to the end of a length of tubing.
• the latching tool and gun assembly is run into the well until it engages a latch coupling secured to the end of a section of fixed well casing at a predetermined position above the interval that is to be penetrated by the sequential firing of a plurality of shaped charges contained in the gun.
• the latch coupling is positioned in the casing.
• the latching tool with the gun attached below is secured to the end of the tubing and run into the casing until the latching tool engages the latch coupling.
• the gun is then fired to perform the multiple same location reservoir penetrations.
• a rig positioned at the well is required for all operations.
• the production tubing is run to finally complete the well before the rig is released.
• the production tubing is usually equipped with a profile nipple for landing the pressure and temperature gauge for taking reservoir pressure and temperature measurements from time to time using a coiled tubing or a wireline device in rigless operations.
• the production tubing is equipped with a latch coupling similar to the one used in the casing in order to be able to perform the rigless operation without the need of the more complex completion described in the prior art.
• a downhole motor, directional tags and a directional survey tool are required for the precise positioning of the gun for the multiple same location penetrations.
• This specialized assembly can then be run into and withdrawn from the profile nipple in the production tubing using a wireline or coiled tubing, neither of which require a rig.
• a motor and directional control tools be operated by personnel at the surface.
• TCP tubing-conveyed perforating
• latching tool of the prior art requires a drilling rig at the surface in operation to handle the tubing that conveys the gun to the desired depth in the well bore.
• perforating guns are available in various configurations and in each case, the key objective in the selection of the gun and the size, nature and set up of the shaped charges is to create a predetermined pattern of perforations over a predetermined wellbore interval.
• a related problem to be solved is how to provide an improved, more cost-effective system and method for initiating the hydraulic fracturing in tight gas reservoirs at a deeper point of penetration having a larger diameter without a rig, i.e., in a rigless operation. It would be highly advantageous to provide a rigless system and method employing robust apparatus and without electronic controls and orienting elements capable of efficiently completing a plurality of reservoir perforations or penetrations at the same position to produce a deeper penetration with a larger diameter before the hydraulic fracturing is commenced.
• the problem can also be stated as how to more quickly and economically position and maintain the gun at the same location for successive or repeated reservoir penetration shots in wells operating without a rig, and to avoid the more complex assemblies that require surface controls and trained technicians to reposition the complex assemblies used with the perforating guns that are deployed by wireline and/or a coiled tubing unit.
• the arrangement of the latch coupling and latching tool in accordance with the method and system of the present invention provides a consistent, reproducible reference at the predetermined depth and orientation for repeated use of the perforating gun in vertical and lateral wells without the need of maintaining a drilling rig at the well site.
• the much less expensive alternative of enabling a coiled tubing unit to position and withdraw the TCP gun results in a significant cost savings as compared to the prior art system that relied on a rig to move the gun.
• coiled tubing unit has the customary trade-recognized meaning of a truck or other mobile mounting, or an apparatus that is skid-mounted and that can be positioned at the wellhead to dispose coiled tubing from a roll into, and withdraw it from the well production tubing.
• the latch coupling is positioned on the production tubing that is run as the final completion of the well and before the rig is released. After the rig is released, the gun that is secured below the latching tool is run by means of coiled tubing or wireline in a rigless operation.
• a latch coupling is assembled to the end of the production tubing, and the production tubing is lowered by the rig to a position above and proximate the target zone.
• the top of the gun is secured to a latching tool that is configured to mate with the latch coupling.
• the latching tool in turn is attached to the free end of a coiled tubing unit.
• the gun is then run inside the production tubing with the coiled tubing in a rigless operation. With the latching tool and the gun inside the production tubing, at the latch coupling depth the latching tool can engage the latch coupling in only one mating position.
• the engagement of the latching tool with the fixed stationary latch coupling assures that the gun is at the same fixed depth and that the gun charges are oriented in the same direction after each gun reload trip to perform multiple penetrations of the same location.
• a latch coupling that is suitable for use in the invention is sold by Halliburton under the brand name "SperryRite". It is designed for use in an advanced reservoir drainage multilateral system. It allows full-bore unrestricted access to the main bore and provides a consistent, repeatable reference for the depth and orientation of multilateral tools. The construction of this Halliburton SperryRite tool and its mode of operation will be described to facilitate an understanding of its use in the present invention.
• the latching tool is constructed with four (4) spring-loaded keys that are located on the lower section of the tool. These keys are driven in the ID of the casing wall with great force. When the tool is run into the well casing, a force of 8000 to 12000 pounds is required to push the tool into the well.
• the keys will only expand when the correct key segment is in the correct recess in the latch coupling. Unless the keys are fully expanded into the correct recesses, the tool will not hold much more weight than that which is required to push the tool into the well. In addition, the square shoulders of the latch keys will not allow rotation once they have "found” and expanded into the correct recesses in the latch coupling.
• the tool is set to release at about 40,000 pounds of straight pulling force, according to the manufacturer's specifications.
• the latch coupling is secured to the production tubing to form an integral part of the last section of production tubing and is placed so that it will be positioned above and in close proximity to the target zone that has been targeted for multiple penetration.
• the latching tool is secured to the end of coiled tubing and the gun is secured to the downhole end of the latching tool and is run in, or lowered into the hole by the coiled tubing, e.g., using a coiled tubing unit. 3. As the gun and the latching tool are run into the production tubing and reach the latch coupling depth, the latching tool engages the latch coupling and sets the gun in a fixed position at the predetermined interval.
• latching tool is released from the latch coupling and pulled out of the hole with the gun for re-loading with new charges for the second run.
• the latching tool and gun are again disengaged by an upward force on the coiled tubing and withdrawn from the wellbore. and the gun is removed from the latching tool.
• latching tools are secured to the production tubing at predetermined positions on the coiled tubing above the gun, and the gun is constructed with multiple drop firing sections.
• the latching tool, latch coupling and the gun are modified for this embodiment.
• the modified latching tool has the capability of unlatching with a downward force in addition to the current and conventional mode of operation in which unlatching is effected by a predetermined upward force.
• the top of the gun will be assembled with three latching tools and the shaped charge portion of the gun will include three firing sections.
• the lower-most latching tool after engagement in the latch coupling will position the lower-most firing section of the gun opposite the target interval in the reservoir that is to be perforated for the first time.
• the section After firing the first charge in this lower-most section, the section will drop to the bottom of the well which is known as the "rat hole".
• the rat hole is additional footage drilled in the well below the production zone to dispose of redundant tools and avoid the cost of retrieving them.
• the gun is then lowered by the application of a downward force to cause the second latching tool to engage with the latch coupling and to position the next or second firing section at the same location as the first gun section.
• the second gun section will penetrate deeper in the same openings created by the first gun section and after firing it will also drop to the bottom of the well.
• the sequence is repeated for the third section of shaped charges that are fired in the same location to further extend the depth of the penetration and enlarge the holes.
• the second and third set of shaped charges that are fitted into the gun are designed and configured to effect the second and subsequent shot into the penetration created by the first shot, the second shot effecting a deeper penetration into the formation and enlarging its diameter.
• the selection and placement of the shaped charges in the gun are well within the skill of the art.
• the gun can also be modified to provide the capability of firing in multiple vertical locations. This enables the gun to be lowered to a different interval in the we 11 bore that is displaced below the first interval. As modified in accordance with the present invention, the gun also has the capability of completing multiple series of discreet firings at the same and different intervals in the reservoir.
• the perforating gun is configured to receive a plurality of first shaped charges and a plurality of second shaped charges and functions in a manner similar to that described above, with the exception that after firing the first and second shaped charges into the perforations in a first interval, the gun is moved to a second interval where the first and second firing procedure is repeated.
• the ability to create deep penetrations by positioning the gun for a first and second firing at the same location without retrieving the gun to the surface for reloading will result in a significant cost savings in bringing the well into production.
• FIG. 1 is an illustration, partly in section, showing a latching tool in an engaged position with a latch coupling which combination would be suitable for use in the practice of this invention
• FIG. 2 is a simplified schematic illustration of a rigless completion in accordance with the present invention in which a coiled tubing unit is positioned at the earth's surface to run and withdraw the perforating gun for multiple penetrations of the reservoir;
• FIG. 3 is a schematic illustration of an apparatus of the invention in which a perforating gun is positioned for penetration of three layers of casing pipes and any cement present between them;
• FIG. 4 is a simplified schematic illustration of a perforating gun in accordance with the invention fitted with first, second and third gun sections and their corresponding latching tools for effecting multiple penetrations without having to retrieve the gun for reloading at the surface.
• FIG. 1 Referring to the partial sectional view of Fig. 1, there is shown a typical latch coupling 30 and latching tool 32 of the prior art that is suitable for use in the practice of the present invention.
• the spring-loaded projecting members 34 of the latching tool include projecting members 36 that engage openings 31 in the latch coupling to assure consistent, repeatable alignment of these elements.
• the projecting members 36 have flat surfaces 37 that prevent the latch coupling from rotating once engaged in the mating openings 41 in the latch coupling 30.
• the latch coupling is configured to receive and engage the latching tool consistently in the same orientation.
• FIG. 2 a well completion is shown in which the latch coupling 30 is secured adjacent to the downhole end of production tubing 40.
• a latching tool 32 secured to a multi-charged gun 50 is shown as lowered by coiled tubing 44 into its engaged position with latch coupling 30.
• the production tubing has been passed through a 4-1/2 inch liner 24, which is in turn positioned inside of a 5-1/2 inch expandable tubular, which in turn is inside of a 7 inch liner 20.
• the annular regions between the inner casings, and the space between liner 20 and the reservoir 1 are cemented.
• a truck-mounted coiled tubing unit 100 is positioned adjacent established wellhead 1 10 at the earth's surface.
• a continuous roll of coiled tubing 102 is passed through guide 104 and into the annulus of the production tubing 40 which is surrounded by the conventional completion casings, including those described above.
• the movement of the coiled tubing in the production tubing is controlled by an operator stationed on the coiled tubing unit.
• the firing of the penetration gun is controlled from the surface by conventional means.
• the first firing is sufficient to penetrate the three concentric casings and penetrate the formation 1 to a first depth 12 as depicted by the broken lines in Fig. 2.
• the operator of the coiled tubing unit 100 applies a sufficient upward force to release the spring-loaded engagement means on the latching tool and the assembly with the spent gun charges is withdrawn from the well.
• the gun 50 can either be removed from the latching tool 32 and replaced with an identical gun having fresh shaped charges, or the spent elements can be removed and replaced with fresh shaped charges 52 for the second run.
• the procedure described above with reference to the first firing is repeated for the second firing and a third firing.
• the resulting second penetration 14a and third penetration 14b following the third run of the gun are illustrated by the respective regions shown in broken and solid lines in Fig. 2.
• the same results can be achieved using the method and system of the present invention utilizing a wireline unit which also obviates the need for a rig at the wellhead.
• the ability to repeatedly run the gun into the well and withdraw it for reloading greatly expedites the operation as compared to the prior art method of removing production tubing using a rig.
• the apparatus required for the present invention is also much simpler than that required for the prior art rigless operation.
• FIG. 3 an alternative well completion is illustrated that represents an advantage associated with the employment of the method and system of the invention.
• the size of the wellbore drilled in tight gas reservoir rock depends upon the overall well design from the surface to the reservoir target zone.
• the target zone is drilled with a 8-3/8" hole; in other wells, the target zone is drilled with a 5-7/8" hole.
• the 8-3/8" hole is cased with 7" pipe liner.
• the 5- 7/8" hole is cased with a 4 1 ⁇ 2" liner.
• the hole drilled in the target zone is left open without a cemented pipe liner.
• a closed hole, or CH completion the target zone is provided with a cemented pipe liner.
• the liner extends from the bottom of the OH to +/- 300 feet inside the casing above the open hole.
• the casing extends to the earth's surface.
• the design of the well will take into consideration the size and positioning of the various tools and fittings required in the practice of the invention as described.
• an additional and unplanned pipes e.g., a casing, liner or expandable must be run to overcome the difficulty in order to enable the continuation of drilling to reach the main target zone.
• a shallower zone is found to be of interest and it is behind more than two casings
• the well engineer is faced with an additional challenge to making deep penetrations into the formation.
• Current perforation practice suffers from providing deep perforations into the formation, especially where the target zone is behind more than two casings.
• the present invention overcomes the limitations and difficulties of conventional perforation practices to perforate more than two casings and can achieve deep perforations that bypass near wellbore damage in a formation with high compressive strength.
• a first trouble zone 4 forced the termination of the run of liner 20 at the depth illustrated.
• a second trouble zone 6 was also encountered at a greater depth and a 5-1/2 inch expandable tubular 22 was put in place to extend the casing 20 towards the target zone 2.
• a 4-1/2 inch liner 24 was then positioned inside the expanded casing 22 to span the target zone.
• the penetration of the formation is achieved by lowering the production tubing 40 with the latch coupling 30 secured proximate its end into the region above the main target zone 2. Thereafter, the coiled tubing 44 to which are secured the latching tool 32 and depending gun 50 with shaped charges are lowered into engagement with the latch coupling 30 and thereby positioned the gun 50 for repeated firing in the main target zone 2 in order to achieve the desired degree of penetration.
• a plurality of penetrations 13 are illustrated schematically in zone 2, which required only the penetration of a single casing 24.
• a secondary target zone 2a was located at a shallower depth, but at the position where three concentric sections of casings were in place.
• repeated firings at the same location enable the casings to be penetrated and the surrounding reservoir rock in the secondary target zone 2a to be penetrated to a suitable depth to provide the desired level of production.
• the gun can be reloaded and returned with the latching tool for engagement with the latch coupling and a third firing to effect even deeper penetration at the same location in the interval.
• the selection of shaped charges for the second and any subsequent firings of the TCP gun in order to produce t he depth and diameter of the penetrations 14 in specific types of reservoir rock are within the skill of the art.
• the method and apparatus of the present invention overcomes tight formation productivity problems because the same interval can be perforated two, three, four or even more times to create the large and deeper holes needed to reach the virgin part of the reservoir for higher well productivity or well injectivity. Additionally, this technique will facilitate stimulation treatment especially in tight formations which are of high compressive strength where achieving deep perforation penetration is particularly difficult. This invention provides for the efficient perforation of tight rock formations to achieve successful hydraulic fracturing treatments.
• the novel configuration of gun assembly 50 is adapted for use with wells that are equipped with a modified latch coupling as described above and saves the coiled tubing unit time that would otherwise be required for the multiple gun trips in the practice of the method described in connection with Figs. 2 and 3.
• the gun assembly 50 attached to tubing 40 includes first, second and third firing sections 50A, 50B and 50C, respectively, each of which is fitted with a plurality of shaped charges 52.
• the tubing is also fitted with three latching tools, represented schematically by elements 32A, 32B and 32C. which are adapted to engage a mating fixed latch coupling in the production tubing when the gun assembly is lowered to the wellbore as described above.
• the gun 50 is lowered so that latching tool 32 A engages the fixed latch coupling (not shown) and the first section 50A of the gun is fired, detached and dropped into the rat hole 1 1 at the bottom of the wellbore 10. Thereafter, the latching tool 32A is disengaged by a downward force and the gun is lowered so that latching tool 32B is engaged with the fixed latch coupling and second section 50B of the gun assembly is in precisely the same position with respect to the first series of penetrations created by the firing of charges 52 in gun section 50A, thereby further penetrating the reservoir.
• the assembly is moved so that latching tool 32C engages the latch coupling and thereby positions the charges of the third section 50C in alignment with the existing penetrations and a third firing is completed.
• the spacing of the latching tools 32 A, 32B and 32C corresponds to the spacing of the shaped charges on the first through third sections of the gun 50.
• the gun assembly 50 can consist of two, three or more sections, each of which will have a corresponding latching tool axially distanced and positioned above to assure proper vertical alignment of the charges in the interval to be penetrated.
• the method and apparatus of the present invention overcomes tight formation productivity problems because the same reservoir interval can be efficiently and economically penetrated two, three or more times without a rig to create the large and deeper holes needed to reach the virgin portion of the reservoir for higher well productivity and/or well injectivity. Additionally, the method facilitates stimulation treatments in especially tight formations of high compressive strength where achieving deep perforation penetration is particularly difficult. This invention provides for the efficient perforation of tight rock formations to achieve successful hydraulic fracturing treatments.
• the present invention provides a cost effective rigless method for implementing more effective and deeper penetration of the reservoir in preparation for hydrofracturing. It also provides a system and method for precise positioning of the gun charges to perforate at the same spot repeatedly after each gun reloading trip that can be implemented relatively quickly employing known robust equipment that is reliable and avoids the need for expensive electronic components operated by skilled technical personnel at the surface.

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Mechanical Engineering (AREA)
• Earth Drilling (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=54884411

Family Applications (1)

Country Status (5)

Families Citing this family (9)

Family Cites Families (7)

• 2014
  • 2014-12-04 US US14/561,053 patent/US20160160620A1/en not_active Abandoned
• 2015
  • 2015-12-01 WO PCT/US2015/063110 patent/WO2016089822A1/en active Application Filing
  • 2015-12-01 EP EP15813197.9A patent/EP3227528A1/en not_active Withdrawn
  • 2015-12-01 BR BR112017011618A patent/BR112017011618A2/pt not_active Application Discontinuation
  • 2015-12-01 AU AU2015355184A patent/AU2015355184A1/en not_active Abandoned

Also Published As

Similar Documents

Legal Events