5 – Creative Ideas Appear
In the 1945 to 1947 timeframe, enthusiasm and optimism was high about possible uses of shaped charges, as were creative ideas that appeared in patents submitted to the U.S. Patent Office. A trio of engineers at the Gulf Research and Development Company (GRDC) in Pittsburgh exemplified this attitude.
Morris Muskat, Floyd Parker, and William Kehl were a team at GRDC. During World War II, Muskat, the senior engineer, guided the group in developing shaped charge designs for the U.S. military.1 After the war, oilfield services companies sought to cooperate with companies and teams, like GRDC, to produce shaped charges for oilfield use. During this effort, the three engineers produced several ideas and detailed them in a patent.2
Reliability is Important
One idea was the reliability of shaped charge configurations. According to the patent, designs following basic configurations could be counted on to penetrate casing and into the formation (Figure 1).
Another illustration in the patent showed a schematic of an apparatus that connected a series of charges to enable multiple detonations (Figure 2).
Groups of charges could be detonated virtually simultaneously by using a “trunk line of explosive rope” such as Primacord™.
Its detonation speed of 6,200 meters per second ensured negligible delays when detonating a cluster of charges.
Additional patent illustrations displayed shaped charges for producing multiple simultaneous perforations at the same level (Figure 3).
The patent also mentioned “the numerous results of our experiments”. Results indicated that varying the angle, material, and weight of the conical liner greatly influenced the perforation depth of the jet.
More Ideas
Not all creative shaped charge patents came from employees of oilfield services companies. Robert Klotz, an engineer who worked for Seismograph Services Corporation, filed his patent application in February 1947.3 This patent described a design that deviated from common shaped charge configurations.
A typical shaped charge surrounded the conical liner with the explosive, and the assembly was then encased in a metal cylinder. Klotz’ patent described an elongated sheet metal cylinder, into which brass or copper conical liners were inserted at the desired locations. Each liner had a rod extending from its apex. The rods could be welded to the container or held in place by tension (Figure 4).
After inserting all the liners, the cylinder was placed into a steel container. A gelatinous explosive, manufactured by the E. I. DuPont de Nemours Company (DuPont), was poured into the assembly. A cover with a central hole was placed on the top. Before the gel solidified, detonation cords were inserted through the hole and into the explosive.
A Key College Contact
Additional creative ideas for shaped charge configurations came from a man named James Murphy. Although Murphy was not an engineer, he had three things going for him. First, his service in the U.S. Army during World War II provided him with first-hand knowledge of shaped charges. Second, he graduated in February 1947 with a Bachelor of Science degree from the Edwy R. Brown School of Petroleum at Marietta College, in Marietta, Ohio. Third, Murphy had befriended Charles Hogg, the head of the School of Petroleum at the college.
Hogg’s expertise and influence enabled Murphy to gain the assistance of Petroleum Explosives Company in Oil City, Pennsylvania, and Producers Torpedo Company in Marietta, Ohio. Murphy had designs for oilfield shaped charges, and these companies were willing to make and test them.
Murphy did not submit a patent application on his designs. He chose to describe them and the test results in the June 1947 issue of The Oil and Gas Journal.4 His article began with brief descriptions of a few designs and how they solved certain oilfield problems. He then focused on a key goal in the oil field: effective penetration of the formation by shaped charges.
Murphy knew several shaped charges might be needed to penetrate the rock adequately and leave clear passageways for the oil and natural gas to move from the formation and into the wellbore. Multiple trips of single shaped charges down the wellbore were costly.
Murphy designed a carrier that was a cylindrical tin shell containing several shaped charges stacked in a spiral arrangement. When the outward-facing charges detonated, their jets penetrated the formation circumferentially around the wellbore. This, according to Murphy, “would make the well flow and clean itself”. His article did not give details about the carrier, but he provided a sketch of it and two more carriers (Figure 5).
In the next three years, 20 patents on shaped charge design were filed by engineers and designers. All expressed confidence in the feasibility of their novel ideas. Sometimes, though, an optimistic approach can overlook serious issues. Shaped charge technology was in its infancy, and designers quickly discovered problems that needed solutions.
References
- Muskat, M. “Development of Follow-Through Projectile,” NDRC Div. 0 Interim Report on Controlled Fragmentation and Shaped Charges, June 15, 1943. pp. 36-45.↑
- Muskat, M., et al., Apparatus for Perforating Well Casings and Well Walls, U.S. Patent number 2,494,256. Filed September 11, 1945.↑
- Klotz, Robert, Method for Shooting Oil Wells, U.S. Patent number 2,630,182. Filed February 19, 1947.↑
- Murphy, James, “New Oil-Well Shooting Method,” The Oil and Gas Journal, June 1947. p. 86.↑
Join the Discussion!
- Can you share any insights on the challenges oilfield engineers and designers faced when adapting military shaped charge technology for well perforation?
- Could you provide further examples or stories of the challenges and breakthroughs shaped charge designers faced as this technology evolved from its infancy?
- Are you aware of any financial strategies or partnerships in the 1946 to 1950 timeframe that advanced shaped charge designs for commercial oilfield applications?
I’d love to hear your perspective. Share your thoughts or answer a question in the comments below!