In 1910 J.C. Swan introduced well perforating to the world with the invention of the first mechanical casing perforator. By 1926 bullet perforating had entered the market. In 1946 perforation using high-energy shaped charges based on military anti-tank explosives was developed. To date, this method remains the industry standard; however, manufacturers of perforating equipment continually strive to establish greater safety, reliability and efficiency.

Over the last several decades E&P technologies have seen tremendous advances. The focus of perforating equipment manufacturers has primarily been on improving the design of the charge rather than altering the deployment of the guns.

Perforating guns have traditionally been deployed with an unpowered casing collar locator (CCL), which is used to identify casing collars downhole and therefore provide a measure of depth control. Mechanical methods used to orient the guns such as sinker bars with eccentered weights and bow-spring centralizers have not evolved and so fail to provide the data verification needed in modern perforating activities such as confirming the accuracy of gun orientation.

Moving beyond status quo
During a new product development strategy session in 2010, Iain Maxted, CTO and founder of Guardian Global Technologies, and John McGrath, vice president of sales and marketing, realized that none of the industry’s perforating equipment manufacturers offered a complete end-to-end deployment system.

To streamline the perforating process, they established integrated electronic safeguards to reduce runtimes, increase operational safety and prevent guns from firing off-depth. They identified an opportunity in the market and saw that Guardian could provide a solution—a single, modular perforating deployment system from the cable head to the detonator.

Having spent years developing advanced perforating and production logging equipment for the oil and gas sector, Guardian possessed a majority of the components needed to create this end-to-end system. For example, Guardian already had commercialized an addressable release tool, a powered swivel joint (PSJ) and a gun brake system. That being said, the development team still faced considerable technical and engineering challenges to create the remaining equipment. Primarily, the products had to be able to withstand perforating shock.

Safer switch in single system
To bring greater efficiency and safety to perforating operations, Guardian developed its patented select fire switch (SFS), which allows operators to address and control multiple detonators from the surface using the company’s intuitive Sentinel software.

Up to 100 SFSs can be deployed in a single run. The SFS exceeds the requirements of the American Petroleum Institute (API) RP 67 code of practice for safe perforating operations. It also features patented break-off tabs for instant visual confirmation of switch status, which eliminates the requirement for radio silence when deploying resistorized detonators.

Efficiency was further enhanced for operators with the creation of Guardian’s multipurpose panel (MPP-C). Combining three panels into one, it integrates the Sentinel acquisition system, a perforating power supply and a telemetry panel into a single control unit, saving operators thousands of dollars as well as critical cabin space.

Designed and tested to meet and exceed the stringent requirements of API RP 67, the MPP-C incorporates a safety switch along with dual perforating firing switches and includes a touchscreen control pad. The MPP-C automatically detects the number of perforating switches and the types of tools in the string and builds the tool string diagram, complete with offsets.

After a lengthy period of planning, designing and testing, the company introduced its ballistics delivery system (BDS) to the market in early 2012. Rather than having to engage two, three or even four suppliers with incompatible equipment for a single ballistics operation—to ensure they could address all potential issues affecting both downhole tools and surface control systems—wireline companies could now source everything needed for ballistics and perforating deployment from one supplier.

Integrated innovation
Guardian provides an integrated ballistics delivery platform encompassing everything from the cable head to the detonator interface. With one control system, one set of surface equipment, one software interface and one telemetry system, all accessed through the BDS, Guardian has introduced new levels of efficiency and simplicity to the perforating and ballistics market.

The equipment is designed for high underbalanced perforating, running heavy/long assemblies, oriented perforating, depth control, reducing fishing risk, and controlling and firing multiple guns in a single string. The amount of time spent in perforating is significantly minimized with the BDS. Operators are able to run in-hole faster, perforate more accurately on depth and, when required, orient the guns to optimize production.

The Guardian BDS also introduced revolutionary ways to advance efficiency and safety. Compared to the traditional practice of using an unpowered CCL to monitor a gun’s movement when pumping the tool string down the well, Guardian’s downhole tension tool allows users to maximize their pump rate and place the tool string in the required position as quickly as possible.

In turn, this increases the number of frack stages performed in a day. In addition to improving pump rates, this tool helps operators avoid the expense of having to fish for a perforating string that has been pumped off the cable. Guardian’s SFS also enables optimized pump rates and facilitates navigating downhole.

Flexible, modular system
The BDS is modular in design to meet the demanding task of perforating horizontal wells in unconventional plays, particularly in the shale basins. If the client requires a basic “pump-down” system, as is often the case in the Marcellus and Utica shales, this need is met with a release tool, CCL, cablehead tension tool and the SFS. Alternatively, if a system is needed to accurately orient the guns to avoid shooting through fiber-optic control lines or to align with the optimum stress direction, as is frequently requested in the Eagle Ford and Permian basins, a PSJ, orientation tool and instrument dynamics controller to anchor the string can be added. In all cases, the tools are “addressable” and are controlled from the surface.

Optimizing frack stages per day
Since Swan’s unveiling of the casing perforator, operators have strived to optimize production and streamline processes. With the introduction of the Guardian BDS, operators can increase their perforating runs, reduce misruns and achieve more frack stages per day—all of which contribute to optimized production.

With the Guardian solution, each stage can support between three and eight guns run with a plug, and wells can achieve in excess of 60 stages. Saving just 10 to 15 minutes in each stage as well as reducing the number of misruns enables operators to perform fracks well above the industry standard.