This disclosure relates in general to oil and gas tools, and in particular, to systems and methods for fracturing operations including setting tools.
In oil and gas production, hydraulic fracturing may be utilized to recover hydrocarbons from an underground formation. Hydraulic fracturing operations may include a cased wellbore that is plugged and perforated, for example using a setting tool to plug the wellbore and one or more perforating guns to explosively form holes through the casing and into the formation. Often, the perforating guns are arranged in series and may be connected by one or more subs to transmit instructions and/or explosive energy for ignition. Additionally, a setting tool may form a portion of the gun string in order to block subsequent flow into the wellbore when fracturing fluid is introduced after perforating. Presently, various ignitors are coupled through the various intermediate subs, which may be positioned at interfaces subject to fluid ingress, misalignment, and the like.
Applicant recognized the limitations with existing systems herein and conceived and developed embodiments of systems and methods, according to the present disclosure, for improved setting tools.
In an embodiment, an assembly for perforating a downhole formation includes a perforating gun, coupled to a downhole conveyance system, the perforating gun including an explosive charge and an uphole contact. The assembly also includes a tandem, coupled to the perforating gun proximate the uphole contact, the tandem including a cartridge assembly communicatively coupled to the downhole contact and a primary igniter communicatively coupled to the cartridge assembly. The assembly further includes an intermediate sub, coupled to the tandem opposite the perforating gun, the intermediate sub receiving at least a portion of the primary igniter, the intermediate sub having a fuse and secondary igniter. The assembly also includes a setting tool coupled to the intermediate sub, the setting tool receiving a setting signal via the secondary igniter.
In an embodiment, a tandem sub for transmitting a setting signal includes a body, the body having coupling components at a first end and a second end. The sub also includes a channel, extending through at least a portion of the body. The sub further includes a cartridge assembly, positioned within the channel, the cartridge assembly having circuitry for transmitting electrical signals from the first end to the second end. The sub also includes a primary igniter, the primary igniter electrically coupled to the cartridge assembly via a downhole contact formed completely within the body.
In an embodiment, a method for forming a perforating gun string includes providing a perforating gun. The method also includes coupling a tandem sub to the perforating gun at a first end, the tandem sub having a cartridge assembly forming an uphole contact with the perforating gun. The method further includes coupling a setting tool to a second send of the tandem sub, opposite the perforating gun, a power charge of the setting tool being explosively coupled to the cartridge assembly.
The present technology will be better understood on reading the following detailed description of non-limiting embodiments thereof, and on examining the accompanying drawings, in which:
The foregoing aspects, features and advantages of the present technology will be further appreciated when considered with reference to the following description of preferred embodiments and accompanying drawings, wherein like reference numerals represent like elements. In describing the preferred embodiments of the technology illustrated in the appended drawings, specific terminology will be used for the sake of clarity. The present technology, however, is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments. Additionally, it should be understood that references to “one embodiment”, “an embodiment”, “certain embodiments,” or “other embodiments” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, reference to terms such as “above,” “below,” “upper”, “lower”, “side”, “front,” “back,” or other terms regarding orientation are made with reference to the illustrated embodiments and are not intended to be limiting or exclude other orientations.
Embodiments of the present disclosure are directed toward systems and methods that may improve the reliability of transmitting signals to setting tools used in perforating gun strings. Various embodiments include a sub or tandem that receives a cartridge assembly for transmitting instructions and/or operational energy to set setting tool. By way of example, the cartridge assembly may include a contact that is closely positioned and/or in contact with a primary igniter. Upon activation, the contact may transmit a voltage to the primary igniter, which ignites the primary igniter and transmits energy to a fuse extending through an intermediate sub. The fuse may provide energy to a secondary igniter, which is utilized to ignite a power charge, which may set the setting tool. Embodiments of the present disclosure may provide a tandem or sub assembly that houses both the cartridge assembly and the primary igniter, among other components. By arranging the cartridge assembly in a common housing with the primary igniter, the likelihood of misalignment or damage during gun string makeup is reduced. For example, often gun strings are formed at a well site, where various components may be exposed to dirt or debris. This dirt or debris may block the contact between the cartridge assembly and the primary igniter, thereby preventing transmission of energy and setting of the tool, which may lead to undesirable additional runs to correct the error. Closely positioning the contact and the primary igniter in a common housing enables a controlled assembly in an environment with a reduced risk of contamination and also reduces assembly on site, thereby simplifying operations.
The wellbore system 100 includes a wellhead assembly 112, shown at an opening of the wellbore 104, to provide pressure control of the wellbore 104 and allow for passage of equipment into the wellbore 104, such as the cable 110 and the tool 102. In this example, the cable 110 is a wireline being spooled from a service truck 114. The wellhead assembly 112 may include a blowout preventer (BOP) 116 (e.g., pressure control device).
In various embodiments, the downhole tool 102 is a perforating system that includes a series of perforating guns 118 coupled together in series. In this embodiment, the perforating guns may include intermediate subs 120 and also a setting tool 122 at and end of the string. In operation, an electrical signal may be transmitted down the wireline 110 to begin fracturing operations, which may include igniting one or more of the guns 118 and also initiating the setting tool 122. The setting tool 122 may include one or more expandable components that block flow to areas downhole of the setting tool 122, thereby enabling fracturing operations to commence after perforating.
Certain fracturing operations may be referred to as plug and perf, where a setting tool is coupled to the gun string to facilitate plugging the well before, during, and/or after perforating operations. The setting tool may be activated using a firing head that contains an igniter. With the introduction of addressable switches, a switch cartridge is incorporated into the gun strings to activate the setting tool. This adds length to the string, additional components, and additional opportunity for error. Switch cartridges may include an electric pin that makes contact with the igniter, and when voltage is applied the igniter is ignited and a flame output initiates the power charge, which sets the plug. Embodiments of the present disclosure may overcome problems with existing methods by incorporating the igniter into the switch cartridge. The electric pin is replaced with the igniter and becomes part of the cartridge, which is inserted prior to running. Accordingly, embodiments may increase the reliability of the tool by eliminating steps of separate igniter assembly, which may lead to missed runs when assembly is performed incorrectly.
In operation, the cartridge assembly 202 may include circuitry to transmit a signal, received from an uphole or surface source, toward the setting tool 122 to enable activation of the setting tool. The illustrated cartridge assembly 202 includes an uphole contact 212 and a downhole contact 214 to transmit information and/or energy between components. For example, the uphole contact 212 may receive an electrical signal that is transmitted along the circuity 216 (e.g., conductors, processors, timers, etc.) of the cartridge assembly 202 toward the downhole contact 214. The downhole contact 214 may include a pin 218 that extends outwardly from the cartridge assembly 202. In operation, the pin 218 may contact and engage a primary igniter 220 positioned within the intermediate sub 210 or the setting tool body 208, in certain configurations.
A voltage may be supplied that ignites the primary igniter 220, which may be a volume sensitive igniter, that is transmitted along the intermediate sub 210 via a fuse or delay 222. The fuse or delay 222 may ignite a secondary igniter 224, which actives the power charge 226 of the setting tool 122. In this manner, the command may be transmitted along the gun string to the setting tool 122. The present configuration has various drawbacks that are addressed and overcome by embodiments of the present disclosure. For example, misalignment or damage of the pin 218 with respect to the primary igniter 220 may cause a misfire event, which would lead to a second tool run in order to set the setting tool 122. These errors increase time and cost at the well site. Because the pin 218 is typically a component extending from the cartridge assembly 202, it is subject to mechanical damage (e.g., bending) as well as exposed to the environment and may be coated or otherwise interact with dust or debris. While operators may attempt to correct these issues at the site, it may be difficult with a crowded well site that is exposed to environmental conditions. Accordingly, embodiments of the present disclosure are directed to a cartridge assembly that may include the primary igniter 220 as an integrated component.
When compared to the configuration of
In the illustrated embodiment, the primary igniter 220 is arranged at a downhole end 308 and extends beyond a tandem downhole face 310. Accordingly, when the intermediate sub 210 is coupled to the downhole end 308, for example via threads, the primary igniter 220 is positioned within the cavity 306. As will be appreciated, various components, such as a primary igniter length, cavity depth, and the like may be particularly selected to facilitate alignment and coupling between the primary igniter 220 and the fuse 222.
Embodiments of the present disclosure may enable the use of fewer parts and simplified assembly at the well site. For example, operators may prepare the gun string and then install the cartridge assembly 302, with the primary igniter 220, into the channel 304 for use. Because sensitive components, such as the downhole contact 214, are not exposed during this operation, the likelihood of damage or error may be decreased. Furthermore, using the cartridge assembly 302 may enable use with existing systems, for example, by substituting an older cartridge that does not include the primary igniter 220. As noted above, the illustrated cartridge assembly 302 eliminates operator assembly of the igniter because the igniter is preassembled in a controller environment and prepared for operation.
Although the technology herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present technology. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present technology as defined by the appended claims.