Background

[0001] In the oil field, boreholes are drilled for extraction and production of oil and gas. In many drilling operations, multi-lateral boreholes are drilled within a single borehole. Moving from one borehole to another without a pressurized surface borehole and without commingling multiple boreholes in a multilateral completion is a challenge.

Brief Description of the Drawings

[0002] Fig. 1 is a schematic illustration of a multi-lateral well.

[0003] Fig. 2 is a schematic illustration of a wellbore with a liner hanger and production tubing.

[0004] Fig. 3 is a schematic illustration of the wellbore of Fig. 2 with a retrievable whipstock.

[0005] Fig. 4 is a schematic illustration of the wellbore of Fig. 3 with a multi-lateral well.

[0006] Fig. 5 is a schematic illustration of the wellbore of Fig. 4 wherein the multi-lateral well includes a production tube, a polished bore receptacle, a crossover and packer.

[0007] Fig. 6 is a schematic illustration of a multi-lateral well where the first multi-lateral well is ready for stimulation using a JIT assembly.

[0008] Fig. 7 is a schematic illustration of a multi-lateral well with a negotiable barrier after stimulation of the first multi-lateral well using a frac string.

[0009] Fig. 8 is a schematic illustration of the multi-lateral well of Fig. 7 with the frac string removed from the stimulated first multi-lateral well.

[0010] Fig. 9 is a schematic illustration of a multi-lateral well with a negotiable barrier in the first multilateral well after stimulation of the second multi-lateral well using the frac string (or JIT system) and a barrier in the second multi-lateral well.

[0011] Fig. 10 is a schematic illustration of a multi-lateral well with the negotiable barrier opened in the first multi-lateral well and the frac string (or JIT) removed from the second multi-lateral well. [0012] Fig. 11 is a schematic illustration of a comingled multi-lateral well. [0013] Fig. 12 is a flow chart showing the operation of the packer barrier.

Detailed Description

[0014] The following detailed description illustrates embodiments of the present disclosure. These embodiments are described in sufficient detail to enable a person of ordinary skill in the art to practice these embodiments without undue experimentation. It should be understood, however, that the embodiments and examples described herein are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and rearrangements may be made that remain potential applications of the disclosed techniques. Therefore, the description that follows is not to be taken as limiting on the scope of the appended claims. In particular, an element associated with a particular embodiment should not be limited to association with that particular embodiment but should be assumed to be capable of association with any embodiment discussed herein.

[0015] Further, while this disclosure describes a land-based production system, it will be understood that the equipment and techniques described herein are applicable in sea-based systems, multi-lateral wells, all types of production systems, all types of rigs, measurement while drilling ("MWD")/logging while drilling ("LWD") environments, wired drillpipe environments, coiled tubing (wired and unwired) environments, wireline environments, and similar environments.

[0016] This disclosure describes a method and apparatus to move completion equipment from one wellbore to another in a multi-lateral well without a pressurized surface wellbore and without comingling fluids from multiple wellbores. The purpose of this method is to avoid interventions. It will allow retrieving a Junction Isolation Tool (JIT) assembly or frac string by isolating the pressure and flow from the lateral(s). This method and apparatus will also allow access to the productive bore by applying pressure above a barrier or removing an internal barrier in the assembly. The barrier may also be opened mechanically so that the assembly can be retrieved from the bore. The applied pressure opens a valve that is activated by absolute pressure applied above and is not affected by differential pressure from below.

[0017] Referring initially to Fig. 1, a wellbore 110 (or drilled hole) extends from a surface (not shown, but indicated by arrow 115 pointing in the direction of the surface) and traverses a formation 120. The formation 120 may also be production horizon. The wellbore 110 may include a casing 125 that is cemented into the wellbore 110 by cement 130. The wellbore 110 may include a first multi-lateral well 135 and a second multi-lateral well 140. The distance between the first multi-lateral well 135 and the second multi-lateral well 140 are not necessarily to scale. The first multi-lateral well 135 may traverse the formation 120 in a direction or angle that is not the same as the second multi-lateral well 140. In some applications, the multi-lateral wells 135, 140 may be parallel within the same formation 120, but extend in different directions within the formation 120. Identifying the multi-laterals wells 135, 140 as "first" and "second" should not be interpreted as limiting the order of completion of the multi-lateral wells. The first multi-lateral well 135 may be completed first or the second multi-lateral well 140 may be completed first. The technique may be applied to a plurality of multi-lateral wells within a wellbore 110 and multiple laterals within a multi-lateral well.

[0018] A tubing string 145 extends through the formation 120 to provide a conduit for stimulation fluids (such as fracking fluids) to travel from the surface 115. Tubing strings 145 may be deployed within the multi-laterals (i.e. first multi-lateral well 135 and second multi-lateral well 140). For purposes of illustration and clarity, the tubing string 145 in the first multi-lateral well 135 is labeled "145 A", and the tubing string 140 in the second multi-lateral well 140 is labeled "145B." A frac string or a Junction Isolation Tool (JIT) (not shown), may be deployed in the wellbore 110. A barrier, such as a negotiable barrier 155, described in more detail in connection with Fig. 7, may be inserted into the first multi-lateral well 135 after stimulation of the first multi-lateral well 135. A negotiable barrier is a barrier that has at least two states: a first state in which it blocks a multi-lateral well and a second state in which it does not block a multi-lateral well. Alternatively, the barrier may be a retrievable bridge plug (RBP).

[0019] The method may begin with drilling the wellbore 110 into the formation 120, as illustrated in Fig. 2. The second multi-lateral well 140 may be drilled in a direction offset from the wellbore 110. The tubing string 145B is placed within the second multi-lateral well 140 to serve as a conduit for oil and gas once the second multi-lateral well 140 is stimulated. The tubing string 145B may include a float shoe 205, a float collar 210, a landing collar 215, and a liner hanger 220 for a cemented installation.

[0020] After the liner hanger 220 is cemented (or in other applications, it can also be an open hole completion), a retrievable whipstock 305 is deployed to a predetermined position within the wellbore

110, as illustrated in Fig. 3. A drill string (not shown) is deployed to drill the first multi-lateral well 135, as illustrated in Fig. 4. Once the first multi-lateral well 135 is drilled, a tubing string 145A, as illustrated in Fig. 5, is deployed into the first multi-lateral well 135. The tubing string 145A may include a float shoe 205, a float collar 210, a landing collar 215, a packer 505, a polish bore receptacle (PBR) 510, and a transition joint (not shown).

[0021] For oil and gas to be produced from the wellbore 110, the first multi-lateral well 135, or the second multi-lateral well 140, and travel to the surface 115, one of the multi-lateral wells 135, 140 must first be stimulated. Note, stimulation may not be required in all instances. In Fig. 6, the first multilateral well 135 is shown being stimulated via tubing string 145 (or using a JIT (not shown)). Thus, in this example, the first multi-lateral well 135 is stimulated first. In other examples, the second multilateral well 140 is stimulated before the first multi-lateral well 135. [0022] After the first multi-lateral well 135 is stimulated, a barrier, such as negotiable barrier 155 (indicated by the dashed box labeled 155), may be deployed into the first multi-lateral well 135 through the tubing string 145, as illustrated in Fig. 7. Alternatively, the barrier may be an RBP. The negotiable barrier 155 may consist of a packer 705, a pressure operated vent (POV) or sliding sleeve 710 (e.g., Halliburton part numbers: 993.02727, 993.02775, 993.02776, 993.02777), and a plugged pipe 715. The plugged pipe 715 may include a mechanically activated device. The plugged pipe 715 may include dissolvable device (such as a dissolvable bridge plug), in which the device dissolves within a predetermined amount of time, or when specific elements (such as saline well fluids) are introduced to the plugged pipe 715. The plugged pipe 715 may include a ceramic device or glass, in which the ceramic device can be breached to allow producing fluids or gas to enter the wellbore 110. The plugged pipe may also include a retrievable plug set in a profile (not shown). The barrier 155 allows the tubing string 145 (or frac string) and/or a junction isolation tool (JIT), and the whipstock 305 to be removed from the wellbore 110, as illustrated in Fig. 8, while isolating the pressure from the previous stimulated multi- laterals (in this case, the first multi-lateral well 135).

[0023] The tubing string 145 (or a frac string) or JIT assemblies (not shown in Fig. 9) are redeployed into the wellbore 110, as illustrated in Fig. 9, and coupled to the second multi-lateral well 145B. The second multi-lateral well 140 is then stimulated. After the second multi-lateral well 140 is stimulated, a retrievable bridge plug (RBP) 905 (or a second negotiable barrier, similar to negotiable barrier 155) is deployed into the second multi-lateral well 140. The RBP 905 (or the second negotiable barrier) allows the JIT (or frac string) to be removed. At this moment, both multi-lateral wells 135, 140 are stimulated, but the oil and gas are prevented from traveling to the surface 115 by the barrier 155 and the RBP 905 (or the second negotiable barrier).

[0024] As illustrated in Fig. 10 (which assumes the use of the negotiable barrier 155 in first multi-lateral well 135), a predetermined amount of pressure (indicated by arrow 1005) is applied at the wellbore 110 (above the first multi-lateral well 135) to open the POV 710 in the first multi-lateral well 135, which allows oil and gas to flow (indicated by arrows 1010 and 1015) into the wellbore 110 through the negotiable barrier 155. The order of opening the first multi-lateral well 135 and the second multi-lateral well 140 may be reversed. In other applications, the multi-lateral well with the negotiable barrier assembly will normally be opened first. [0025] The POV (or sleeve) 710 is opened by absolute pressure (e.g. 1000 psi). The opening pressure (i.e., pressure 1005) on the POV (or sleeve) 710 is not affected by differential pressure (i.e., the difference between the pressure 1005 and the internal pressure of the first multi-lateral well 135). The POV (or sleeve) 710 opening pressure can be adjusted. The POV (or sleeve) 710 may be isolated from the tubing pressure by a break plug (not shown). The pressure 1005 forces the sleeve to move and uncover flow ports (not shown), thereby allowing oil and gas to enter the hollow center of the POV (sleeve) 710.

[0026] As illustrated in Fig. 11, an operator (i.e. XYZ Oil & Gas Company) can allow the oil and gas from the second multi-lateral well 140 to flow into the wellbore 110 (indicated by arrows 1105 and 1110) and to the surface 115 by removing the RBP 905 from the second multi-lateral well 140 (or by opening a negotiable barrier, as described above). As a result, the oil and gas from the first multi-lateral well 135 and the second multi-lateral well 140 are produced in the wellbore 110 and travel to the surface 115. In other applications, the frac string or JIT assembly does not need to be removed from the wellbore 110 to comingle fluids from the multi-lateral wells 135 and 140.

[0027] In operation, as illustrated in Fig. 12 (which assumes that the barrier of the first lateral well is a negotiable barrier and that the barrier of the second lateral well is an RBP), a completion apparatus (such as tubing string 145) is coupled to a first lateral well (such as first multi-lateral well 135) extending from a borehole (such as wellbore 110) (block 1205). The first lateral well (such as first multi-lateral well 135) is completed (block 1210). The first lateral well (such as first multi-lateral well 135) is isolated from the borehole (such as wellbore 110) with a negotiable barrier (such as negotiable barrier 155) that prevents fluids from flowing from the first lateral well (such as first multi-lateral well 135) in the borehole (such as wellbore 110) (block 1215). The completion apparatus (such as tubing string 145) is decoupled from the first lateral well (such as first multi-lateral well 135) (block 1220). The completion apparatus (such as tubing string 145) is coupled to a second lateral well (such as second multi-lateral well 140) extending from the borehole (such as wellbore 110) (block 1225). The second lateral well (such as second multi-lateral well 140) is then completed (block 1230). The second lateral well (such as second multi-lateral well 140) is plugged with a removable plug (such as retrievable bridge plug 905) after the second lateral well (such as second multi-lateral well 140) is completed (block 1235). The completion apparatus (such as tubing string 145 or JIT assembly) is optionally decoupled from the second later well (such as second multi-lateral well 140) (block 1240). Pressure is applied to the negotiable barrier (such as negotiable barrier 155) to allow fluids to flow from the first lateral well (such as first multi-lateral 130) into the borehole (such as wellbore 110) (block 1240). The removable plug (such as RPB 905) is removed from the second lateral well (such as second multi-lateral well 140) (block 1250). Fluids from the second lateral well (such as second multi-lateral well 140) are then produced into the borehole (such as wellbore 110) (block 1255). [0028] In one aspect, a method features coupling a completion apparatus to a first lateral well extending from a borehole. The first lateral well is completed. The completed first lateral well is isolated from the borehole with a first barrier that prevents fluids from flowing from the first lateral well into the borehole. The completion apparatus is decoupled from the first lateral well. The completion apparatus is coupled to a second lateral well extending from the borehole. The second lateral well is completed. The first barrier is opened to allow fluids to flow from the first lateral well into the borehole.

[0029] Implementations may include one or more of the following. The first barrier may include a negotiable barrier. Opening the first barrier may include applying pressure to the negotiable barrier to allow fluids to flow from the first lateral well into the borehole. Opening the first barrier may include mechanically opening the negotiable barrier to allow fluids to flow from the first lateral well into the borehole. Opening the first barrier may include dissolving a dissolvable device in the negotiable barrier to allow fluids to flow from the first lateral well into the borehole. Opening the first barrier may include breaching a breachable device in the negotiable barrier to allow fluids to flow from the first lateral well into the borehole. The first barrier may include a removable plug. Fluids from the second lateral well may be produced into the borehole. The second lateral well with a second barrier may be plugged after completing the second lateral well. The second barrier may include a negotiable barrier. Opening the second barrier may include applying pressure to the negotiable barrier to allow fiuids to flow from the second lateral well into the borehole. Opening the second barrier may include mechanically opening the negotiable barrier to allow fluids to flow from the second lateral well into the borehole. Opening the second barrier may include dissolving a dissolvable device in the negotiable barrier to allow fluids to flow from the second lateral well into the borehole. Opening the second barrier may include breaching a breachable device in the negotiable barrier to allow fluids to flow from the second lateral well into the borehole. The second barrier may include a removable plug. The second barrier may be opened after opening the first barrier. The second barrier may be opened after pressure of fluids in the second lateral well match the pressure of fluids in the first lateral well. The barrier may be assembled using a pressure- activated vent having an uphole side and a downhole side. The barrier may be assembled using a packer coupled to the uphole side of the pressure-activated vent. The barrier may be assembled using a plug coupled to the downhole side of the pressure-activated vent. The barrier may be opened by applying pressure from the surface.

[0030] In one aspect, an apparatus features a pressure-activated vent having an uphole side and a downhole side. A packer is coupled to the uphole side of the pressure-activated vent. A plug is coupled to the downhole side of the pressure-activated vent.

[0031] Implementations may include one or more of the following. The plug may block a passage through the pressure-activated vent and may allow pressure within the pressure-activated vent to be increased by increasing the pressure on the uphole side of the pressure-activated vent. [0032] In one aspect, a system features a borehole. The system features a first lateral well extending from the borehole. The system features a second lateral well extending from the borehole. The system features a barrier assembly positioned in the first lateral well to prevent fluids from flowing from the first lateral well into the borehole. The system features a completion apparatus coupled to the second lateral well. [0033] Implementations may include one or more of the following. The barrier assembly may include a pressure-activated vent having an uphole side and a downhole side. A packer may be coupled to the uphole side of the pressure-activated vent. A plug may be coupled to the downhole side of the pressure- activated vent. [0034] The word "coupled" herein means a direct connection or an indirect connection.

[0035] The text above describes one or more specific embodiments of a broader invention. The invention also is carried out in a variety of alternate embodiments and thus is not limited to those described here. The foregoing description of an embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.