BACKGROUND OF THE INVENTION

Generally, when completing a subterranean well for the production of fluids, minerals, or gases from underground reservoirs, several types of tubulars are placed downhole as part of the drilling, exploration, and completions process. These tubulars can include casing, tubing, pipes, liners, and devices conveyed downhole by tubulars of various types. Each well is unique, so combinations of different tubulars may be lowered into a well for a multitude of purposes.

A subsurface or subterranean well transits one or more formations. The formation is a body of rock or strata that contains one or more compositions. The formation is treated as a continuous body. Within the formation hydrocarbon deposits may exist. Typically a wellbore will be drilled from a surface location, placing a hole into a formation of interest. Completion equipment will be put into place, including casing, tubing, and other downhole equipment as needed. Perforating the casing and the formation with a perforating gun is a well known method in the art for accessing hydrocarbon deposits within a formation from a wellbore.

Explosively perforating the formation using a shaped charge is a widely known method for completing an oil well. A shaped charge is a term of art for a device that when detonated generates a focused output, high energy output, and/or high velocity jet. This is achieved in part by the geometry of the explosive in conjunction with an adjacent liner. Generally, a shaped charge includes a metal case that contains an explosive material with a concave shape, which has a thin metal liner on the inner surface. Many materials are used for the liner; some of the more common metals include brass, copper, tungsten, and lead. When the explosive detonates, the liner metal is compressed into a super-heated, super pressurized jet that can penetrate metal, concrete, and rock. Perforating charges are typically used in groups. These groups of perforating charges are typically held together in an assembly called a perforating gun. Perforating guns come in many styles, such as strip guns, capsule guns, port plug guns, and expendable hollow carrier guns.

Perforating charges are typically detonated by detonating cord in proximity to a priming hole at the apex of each charge case. Typically, the detonating cord terminates proximate to the ends of the perforating gun. In this arrangement, an initiator at one end of the perforating gun can detonate all of the perforating charges in the gun and continue a ballistic transfer to the opposite end of the gun. In this fashion, numerous perforating guns can be connected end to end with a single initiator detonating all of them.

The detonating cord is typically detonated by an initiator triggered by a firing head. The firing head can be actuated in many ways, including but not limited to electronically, hydraulically, and mechanically.

Expendable hollow carrier perforating guns are typically manufactured from standard sizes of steel pipe with a box end having internal/female threads at each end. Pin ended adapters, or subs, having male/external threads are threaded one or both ends of the gun. These subs can connect perforating guns together, connect perforating guns to other tools such as setting tools and collar locators, and connect firing heads to perforating guns. Subs often house electronic, mechanical, or ballistic components used to activate or otherwise control perforating guns and other components.

Perforating guns typically have a cylindrical gun body and a charge tube, or loading tube that holds the perforating charges. The gun body typically is composed of metal and is cylindrical in shape. Charge tubes can be formed as tubes, strips, or chains. The charge tubes will contain cutouts called charge holes to house the shaped charges.

It is generally preferable to reduce the total length of any tools to be introduced into a wellbore. Among other potential benefits, reduced tool length reduces the length of the lubricator necessary to introduce the tools into a wellbore under pressure. Additionally, reduced tool length is also desirable to accommodate turns in a highly deviated or horizontal well. It is also generally preferable to reduce the tool assembly that must be performed at the well site because the well site is often a harsh environment with numerous distractions and demands on the workers on site.

Currently, perforating guns are often assembled and loaded at a service company shop, transported to the well site, and then armed before they are deployed into a well. Sometimes perforating guns are assembled and armed at the well site. Because the service company shop often employs a single gun loader, maintaining close control on the gun assembly/loading procedures can become difficult. Accordingly, quality control on the assembled/loaded guns may be improved by reducing the amount of assembly necessary at the service company shop.

Electric initiators are commonly used in the oil and gas industry for initiating different energetic devices down hole. Most commonly, 50-ohm resistor initiators are used. Other initiators and electronic switch configurations, such as the Hunting ControlFire technology and DynaSelect technology, are also common.

Following industry safe practices, an electric initiator must always remain shunted, except for during specific uses. This shunt is an electrical short which prevents electrical energy from initiating the device unexpectedly, such as due to radio frequency energy or stray voltage. Other designs, such as short, looped, or no leg wires may mitigate the risk of radio frequency issues.

If the shunt is to be removed, either for arming purposes or for connecting it to an electronic switch, then the initiator must be placed in a safety housing while the shunt is removed. Generally, this requires electric initiators to have lead wires which are exposed outside of the safety housing so as to allow someone to remove the shunt and connect the initiator safely.

The process of removing the initiator shunt is commonly done in the field because most US and all international regulations prohibit the transportation of initiators inside of a perforating gun or other device. Therefore, in the event of a misrun, the initiator must be removed from the perforating gun or other device and the shunt must be re-installed before transporting.

Removal of the shunt, making wiring connections, or replacing the shunt are all inefficient processes. They require leads on the initiator which increases the working footprint and requires the use of additional safety devices such as an initiator safety housing which is bulky. Problems in wiring can lead to misruns. Having to reapply the shunt is tedious and requires proper training to ensure it is done correctly before offering the devices for transport.

Various companies have attempted to remedy these issues. Examples include pairing the initiator directly to an electronic switch in a single package. This solution is non-ideal because it increases the size and fixes the geometry of the initiator, putting additional constraints on its storage and application. The initiator must be used in a specific configuration and hardware. This solution does not prove versatility. Hunting resolves the issues by assembling the initiator to an electronic switch in a controlled manufacturing environment and offers the product as the ControlFire Assembly. This solution increases the size and has exposed wires connecting different components. It provides much more flexibility in which devices it can be used. However, there is a mechanical shunt that must be removed and is sometimes forgotten, resulting in a misrun. This assembly, as well as variations such as the ControlFire Cartridge, utilizes large packaging which takes up significant magazine storage space at a cost to the customer.

Setting a bridge plug typically requires setting a “slip” mechanism that engages and locks the bridge plug with the casing and energizing the packing element in the case of a bridge plug. This requires large forces, often in excess of 20,000 lbs. The activation or manipulation of some setting tools involves the activation of an energetic material such as an explosive pyrotechnic or black powder charge to provide the energy needed to deform a bridge plug. The energetic material may use a relatively slow burning chemical reaction to generate high pressure gases. One such setting tool is the Model E-4 Wireline Pressure Setting Tool of Baker International Corporation, sometimes referred to as the Baker Setting Tool.

The pressure from the power charge igniting is contained with the power charge chamber by the sealed firing head. The pressure builds in the chamber and causes a floating first piston to move down through the tool, compressing the oil reservoir through a small hole in a connector sub.

A jet cutter is an explosive shaped charge that has a circumferential V-type shape. The explosive is combined with a liner. The components are all contained in a housing. The jet cutter is lowered to the desired point in a well where the separation of existing tubulars is desired. Firing a jet cutter generates a high energy plasma jet, typically in 360 degrees of direction, that will severe any adjacent tubulars.

SUMMARY OF EXAMPLE EMBODIMENTS

An example embodiment may include a modular initiator assembly having a receptacle having a boxlike portion adapted to couple a plurality of conductors and an extending connection portion having a pair of pincer electrical contacts, and a wedge shaped protrusion located in between the pair of electrical contacts, a connector adapted to accept the connection portion of the receptacle and have a pair of electrically conductive blades therethrough, each blade having a side springing extension that contacts each other, wherein the installation of the receptacle into the connector causes the pincer electrical contacts to first electrically couple the plurality of conductors to the corresponding blades, which are shunted due to the springing extensions, and then second, when fully inserted, the wedge shaped protrusion separates the springing extension to electrically unshunt the initiator.

A variation of the example embodiments may include having a shell coupled to the connector and having an initiator located within the shell, wherein the initiator is activated via an electrical signal from the plurality of conductors coupled to the receptacle. The shell may contain a resistor based bridgewire initiator. The shell may contain an exploding bridge wire initiator. The shell may contain an exploding foil initiator. The shell may contain a high explosive. It may include a plurality of resistors within the shell. It may include a circuit board, in which the receptacle is hard mounted to the circuit board. The receptacle may be connected to the circuit board with a plurality of conductors. The modular initiator assembly may be used to initiate a perforating gun. The modular initiator assembly may be used to initiate a cutter. The modular initiator assembly may be used to initiate a setting tool.

An example embodiment may include a gun string assembly having a first perforating gun suspending from a wireline, a switch tandem having an inner bore, coupled to and located downhole from the first perforating gun, a second perforating gun coupled to and located downhole from the switch tandem, a modular initiator assembly disposed in the inner bore of the switch tandem further having a receptacle having a boxlike portion adapted to couple a plurality of conductors and an extending connection portion having a pair of pincer electrical contacts, and a wedge shaped protrusion located in between the pair of electrical contacts, a connector adapted to accept the connection portion of the receptacle and have a pair of electrically conductive blades therethrough, each blade having a side springing extension that contacts each other, wherein the installation of the receptacle into the connector causes the pincer electrical contacts to first electrically couple the plurality of conductors to the corresponding blades, which are shunted due to the springing extensions, and then second, when fully inserted, the wedge shaped protrusion separates the springing extension to electrically unshunt the plurality of conductors.

An example embodiment may include a method for connecting an initiator to an electrical source by connecting a receptacle to a circuit board and then installing the initiator into the receptacle wherein the process of installation first electrically connects the initiator to the circuit board and then disengages the shunt in the initiator.

An example embodiment may include a method for detonating a perforating gun string including assembling a perforating gun string, coupling a first initiator to a modular the initiator assembly further comprising connecting a plurality of conductors from a circuit board to a receptacle, shunting the plurality of conductors by first plugging it in partially into a connector, unshunting the plurality of conductors by fully inserting it into a connector, wherein the plurality of conductors is electrically engaged to a initiator only when fully inserted into the connector, lowering a perforating gun string downhole to a predetermined location, firing the modular initiator assembly, wherein the modular initiator assembly is coupled to a detonating cord, and detonating a perforating gun coupled to the detonating cord.

An example embodiment may include a method for assembling a perforating gun string comprising coupling a first initiator to a receptacle to form a modular initiator assembly, wherein the receptacle is attached to the circuit board and the first initiator is self-shunted, plugging the initiator into the receptacle, and maintaining the shunt during the installation of the initiator to the receptacle, wherein no safety housing is necessary.

An example embodiment may include a method for assembling a perforating gun string comprising coupling the receptacle with a plurality of conductors to a safe circuit, coupling a first initiator to the receptacle to form a modular initiator assembly, wherein the receptacle is attached to the circuit board and the first initiator is self-shunted, plugging the initiator into the receptacle, and maintaining the shunt during the installation of the initiator to the receptacle, wherein no safety housing is necessary.

The maintaining of the shunt may protect the initiator from stray voltage. The maintaining of the shunt may protect the initiator from stray electrical energy. The maintaining of the shunt may protect the initiator from stray radio frequency signals. It may include installing the modular initiator assembly into a perforating gun string. It may include lowering a perforating gun string downhole to a predetermined location. It may include firing the modular initiator assembly, wherein the modular initiator assembly is coupled to a detonating cord. It may include firing the modular initiator assembly, wherein the modular initiator assembly is coupled to a booster. It may include detonating a perforating gun coupled to the detonating cord.

An example embodiment may include a method for connecting an initiator having a connector to an electrical source comprising connecting a plurality of conductors from a circuit board to a receptacle, electrically coupling the receptacle to a connector, maintaining the shunt by first plugging the receptacle partially into the connector, shunting the plurality of conductors when the receptacle is partially plugged into the connector, and unshunting the plurality of conductors by fully inserting the connector and the receptacle, wherein the plurality of conductors is electrically coupled to an initiator. A variation of the example embodiment may include removing the initiator from the receptacle, wherein the removal of the initiator from the receptacle automatically shunts the initiator.

