Compact setting tool

Abstract

A compact setting tool that sets a packer or bridge plug in a wellbore and then self bleeds the gas pressure prior to pulling the string out of the wellbore.

Claims

1. A method for setting a plug in a borehole comprising: activating a firing head within a setting tool; starting a gas pressure generating chemical reaction; pressurizing a chamber located within a cylinder with the generated gas pressure; moving a piston disposed within the setting tool in a first axial direction with the generated gas; controlling the rate of piston movement by metering a fluid between two chambers; moving the cylinder in the first axial direction with the generated gas; expanding a seal radially against an inner wall of a borehole casing; separating the seal from the setting tool; relieving the gas pressure in the chamber when the moving piston travels a predetermined linear distance.

2. A method as in claim 1 further comprising placing a setting tool in a borehole at a predetermined location for installing a bridge plug.

3. A method as in claim 1 further comprising equalizing pressure of a first quantity of oil within the setting tool with the wellbore pressure by moving the piston the predetermined linear distance in the first axial direction.

4. A method as in claim 1 further comprising equalizing pressure of a first quantity of gas within the setting tool with the wellbore pressure by moving the piston the predetermined linear distance in the first axial direction.

5. A method as in claim 1 wherein separating includes shearing a shear stud coupled between a setting tool and a radially expanded seal.

6. A method as in claim 1 further comprising removing the setting tool from the borehole after setting a bridge plug.

7. The method as in claim 1 wherein the radially expanded seal is a bridge plug.

8. The method as in claim 1 wherein the radially expanded seal is a packer.

9. The method as in claim 1 wherein the controlling the rate of piston movement is determined by sizing a thru hole for the metering fluid to travel through.

10. The method as in claim 1 wherein the metering fluid is an oil.

11. The method as in claim 1 further comprising absorbing mechanical shock with the fluid metered between two chambers.

12. The method as in claim 1 wherein the relieving the gas pressure occurs while the setting tool is still located within the borehole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings in which reference numbers designate like or similar elements throughout the several figures of the drawing. Briefly:

(2) FIG. 1 depicts a cross-sectional side view of a tool string.

(3) FIG. 2 depicts a cross-sectional side view of a setting tool.

(4) FIG. 3 depicts a cross-sectional side view of a tool string after deploying a bridge plug.

(5) FIG. 4 depicts a cross-sectional side view of a setting tool.

DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

(6) In the following description, certain terms have been used for brevity, clarity, and examples. No unnecessary limitations are to be implied therefrom and such terms are used for descriptive purposes only and are intended to be broadly construed. The different apparatus, systems and method steps described herein may be used alone or in combination with other apparatus, systems and method steps. It is to be expected that various equivalents, alternatives, and modifications are possible within the scope of the appended claims.

(7) An example embodiment is shown in FIG. 1 includes a cablehead assembly 800 which has a wireline 801 coupled to the uphole end of a fish neck assembly 900. A casing collar locator 700, sometimes abbreviated CCL, is located downhole from and coupled to the downhole end of the fish neck assembly 900. A quick change assembly 600 is located downhole from and coupled to the downhole end of the casing collar locator assembly 700. A firing head assembly 500 is located downhole from and coupled to the downhole end of the quick change assembly 600. A setting tool assembly 100 is located downhole from and coupled to the downhole end of the firing head assembly 500. The downhole end of the setting tool assembly 100 is coupled to a setting sleeve 200 and a tension mandrel 300. The tension mandrel 300 is coupled to a bridge plug 400 using a shear stud 401.

(8) In operation a signal from the wireline 801 causes a signal to the firing head assembly 500 that ignites a chemical power charge. The expanding gas generated from the power charge causes the setting tool assembly 100 to mechanically extend in such a way that the setting sleeve 200 moves downhole relative to the tension mandrel 300, which stays stationary. The setting sleeve 200 mechanically collapses the bridge plug 200, which causes it to expand and seal off the casing in which the tool string is located. After the bridge plug 200 is expanded, sufficient stress builds up in the shear stud 401 to cause it to separate from the bridge plug. Once separated, the rest of the tool string can be moved uphole while the bridge plug stays in place in the casing.

(9) FIG. 2 shows a close up view of the setting tool assembly 100. On the uphole side (left side, or top side depending on its orientation) there is a top adaptor 101 configured to couple to a quick change assembly 500. The top adaptor 101 is sealed to the interior of the long cylinder 102 via o-rings 115. Long cylinder 102 has an axial inner thru bore 131 that extends the length of long cylinder 102. The downhole portion of the top adaptor 101 has a bore 126 that forms an uphole end of a pressure chamber. A power charge chamber piston 110 is located within the long cylinder 102, downhole from the top adaptor 101. The long cylinder 102 has a piston head 125 that is sealed to the interior of the long cylinder 102 via o-rings 119. The long cylinder 102 has a bore 127 extending from its uphole end. Bore 127 forms the bottomhole end of a pressure chamber. Power charge 117 is located within bore 126 and bore 127.

(10) Long cylinder 102 has a first undercut 122 and a second undercut 128.

(11) A bottom metering piston 109 is coupled to the power charge chamber piston 110 and held in place with set screw 112. The bottom metering piston 109 is sealed to the interior of the long cylinder 102 via o-rings 121. The bottom metering piston 109 has a thru hole 123 that acts as a bleed port. A nylon plug 111 initially seals the uphole end of thru hole 123 prior to setting. The piston rod 124 extends downhole from the bottom metering piston 109 and is coupled to the crosslink connection 107. Piston rod 124 extends thru bore 132 of cylinder head 103. Thru bore 132 has o-rings 116 that seal against the majority of the length of piston rod 124. Piston rod 124 has a neck portion 140 located proximate to the bottom metering piston 109. The volume between piston rod 124, the interior of long cylinder 102, cylinder head 103, and bottom metering piston 109 is an oil reservoir and is typically filled with oil during assembly.

(12) Cylinder head 103 is coupled to the downhole end of long cylinder 102. Cylinder head 103 is sealed to the interior of long cylinder 102 using o-rings 120. Cylinder head 103 is sealed to the exterior of the piston rod 124 via o-rings 116. Cylinder head 103 is coupled to the slotted mandrel 106 and further held in place to slotted mandrel 106 using set screw 114. The crosslink connection 107 is slideably engaged within the slotted mandrel 106. Slotted mandrel 106 is coupled to the tension mandrel 300.

(13) Crosslink retention ring 105 is couples the crosslink housing 104 to the crosslink 108 using set screw 113. Crosslink 108 and crosslink housing 104 are slideably engaged about the exterior of slotted mandrel 106. Crosslink 108 is slideably engaged with the slots 130 of the slotted mandrel 106. Crosslink housing 104 is coupled to the setting sleeve 200.

(14) Operating the described embodiment includes assembling the tool string, lowering it into a wellbore, using the casing collar locator assembly 700 to accurately determine the position of the tool string, positioning the bridge plug 400 at a desired location within the wellbore, igniting the power charge 117 via a signal from the wireline 801 to the firing head assembly 500, extending the setting tool assembly 100 using the gases from the power charge 117, setting the bridge plug 400 with the setting sleeve 200 moving downhole while the tension mandrel 300 remains stationary, shearing the shear stud 401, venting the power charge gases via undercuts 122, 128, and neck 140, then pulling the depressurized tool string uphole. An advantage of this example embodiment is that the setting tool assembly self bleeds the power charge gases, therefore the setting tool isn't pressurized with 10-20 ksi of gas when it is removed from the wellbore.

(15) The volume defined by the power charge chamber piston 110, the interior of long cylinder 102, and the bottom metering piston 109 is an oil reservoir 129 that is left empty upon installation. The tool string is lowered downhole until the bridge plug is at a predetermined downhole position. A command through the wireline 801 instructs the firing head assembly 500 to ignite the power charge 117. The power charge 117 ignition produces gases at high pressure, which expands against bores 126, 127, and the interior of long cylinder 102. The expansion will start to move the combination of power charge chamber piston 110, bottom metering piston 109, piston rod 124, crosslink connection 107, crosslink retention ring 105, crosslink housing 104, and setting sleeve 200 downhole. When the power charge chamber piston 110 moves downhole due to the gas release from the ignited power charge 117, the pressure in the reservoir 118 increases until the nylon plug 111 pops out into the oil reservoir 129, thus allowing oil to move uphole via thru hole 123. Thru hole 123 is sized to provide a metering effect as the oil moves uphole, thus slowing the rate that the combination of power charge chamber piston 110, bottom metering piston 109, piston rod 124, crosslink connection 107, crosslink retention ring 105, crosslink housing 104, and setting sleeve 200 moves linearly downhole. The downward movement will cause the bridge plug 400 to radially expand as the setting sleeve 200 moves downhole versus the tension mandrel 300 remaining stationary. After setting the radially expanded bridge plug 400, the continuing downhole movement of the combination will cause the shear stud 401 to shear off. After shearing the shear stud 401, the combination will continue moving a predetermined linear distance downhole, at which point the o-rings 115 will disengage at undercut 122, o-rings 121 will disengage at undercut 128, and o-rings 116 will disengage at neck 140. At undercut 121 and 128, o-rings 115 and 121, respectively, cannot hold any pressure. O-rings 116 at neck 140 cannot hold pressure. The loss of the o-rings 115, 121, and 116 sealing ability results in the pressurized gases and the oil venting out of the setting tool assembly via slots 130 in the slotted mandrel 106.

(16) FIG. 3 shows the tool string after the setting tool assembly 100 has deployed. Cablehead assembly 800 has a wireline 801 coupled to the uphole end of a fish neck assembly 900. A casing collar locator 700 is located downhole from and coupled to the downhole end of the fish neck assembly 900. A quick change assembly 600 is located downhole from and coupled to the downhole end of the casing collar locator assembly 700. A firing head assembly 500 is located downhole from and coupled to the downhole end of the quick change assembly 600. A setting tool assembly 100 is located downhole from and coupled to the downhole end of the firing head assembly 500. The downhole end of the setting tool assembly 100 is coupled to a setting sleeve 200 and a tension mandrel 300. Since the setting operation has already occurred, the tension mandrel has sheared stud 401 and is separated from the bridge plug.

(17) FIG. 4 shows in detail what happens within the setting tool assembly 100 after the bridge plug is installed in the wellbore. Top adaptor 101 remains in place. The power charge chamber piston 110, bottom metering piston 109, piston rod 124, crosslink connection 107, crosslink retention ring 105, crosslink housing 104, and setting sleeve 200 have slideably moved downhole in relation to the long cylinder 102. The slotted mandrel 106, which is coupled to the long cylinder 102 via cylinder head 103 and set screw 114, is stationary. Since the tension mandrel 300 is coupled to the slotted mandrel 106, it has also remained stationary.

(18) O-rings 115, 120, and 116 are no longer sealing because they are in contact with undercuts 122, 128, and neck 140, respectfully. Therefore, all gas and oil pressure has been relieved through the o-rings 115, 120, and 116 and through the slots 130 in slotted mandrel 106 to the borehole.

(19) A bridge plug is used in the examples disclosed herein, however several other tools could be used in this application, such as packers, which may be deployed using a setting tool assembly as disclosed herein.

(20) Although the invention has been described in terms of embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto. For example, terms such as upper and lower or top and bottom can be substituted with uphole and downhole, respectfully. Top and bottom could be left and right, respectively. Uphole and downhole could be shown in figures as left and right, respectively, or top and bottom, respectively. Generally downhole tools initially enter the borehole in a vertical orientation, but since some boreholes end up horizontal, the orientation of the tool may change. In that case downhole, lower, or bottom is generally a component in the tool string that enters the borehole before a component referred to as uphole, upper, or top, relatively speaking. The first housing and second housing may be top housing and bottom housing, respectfully. Terms like wellbore, borehole, well, bore, oil well, and other alternatives may be used synonymously. Terms like tool string, tool, perforating gun string, gun string, or downhole tools, and other alternatives may be used synonymously. The alternative embodiments and operating techniques will become apparent to those of ordinary skill in the art in view of the present disclosure. Accordingly, modifications of the invention are contemplated which may be made without departing from the spirit of the claimed invention.