By: Gary M. Kane
The year was 1911 in Summerland, California. There were approximately twelve wharves extending from the Summerland beach heading offshore; each wharf had at least twenty oil wells drilled through it. A structural problem arose and someone was needed to go underwater to repair it – Albert Christie arrived on the scene. An entrepreneur and inventor outfitted with no manufactured dive gear, Mr. Christie designed and built his dive equipment, then successfully made the dive and the wharf repairs. This was the first time a diver had any known contact with the oil industry. Fast forward to 1938 – Superior Oil’s Creole Field in the Gulf of Mexico. A construction barge had sunk and Superior Oil hired W. Horace Williams Construction Company to salvage it. They, in turn, hired Al Warriner, a mechanical engineer, to build the equipment necessary to perform the diving support during the salvage. This was the first known use of a diver in the oil patch in the Gulf of Mexico (GOM).
From 1938 until the early 1960’s the U.S. Navy was the leader in technological advancements in diving. However, that all changed in 1962 when Dan Wilson made the first 400-foot surface dive on helium and oxygen off the coast of Santa Barbara, California. The dive was made to prove to the oil industry that his company could handle the deeper depths the industry was moving toward. Since then, diving has progressed to the deepest dive ever made in the GOM at 1,072 feet achieved by Global Industries. The industry has gone from one diver in total working in the GOM to averaging between 500 and 600 divers working every day.
So what does it take to manage a successful diving operation in the Gulf of Mexico? There are four key drivers – water depth, diving mode selection, diving platform selection and tool selection. The depth of the water and the complexity of the project will determine the diving mode and have an impact on diving platform selection and tool selection.
Water depth is always the first question when setting up a dive operation. Water depths that require divers range from 0 to 1,000 feet in the GOM, with the majority of diving work in less than 400 feet. Water depth, as well as diving mode, defines the amount of time a diver can spend in the water. In deep water, time as well as capable diving platform assets are limited. In very shallow water, there is no limitation on time but there are fewer capable diving platform assets. The logistical and technical challenges of projects in very shallow water should not be underestimated. There have been as many diver fatalities in shallow water as there have been in deep water. The diving depth will also have a big part in determining the complexity and cost of the project.
Three diving modes are used in the GOM – surface air diving, surface mixed gas diving and saturation diving. Each mode has depth limitations, time constraints and cost considerations.
Surface air diving is the most commonly used mode in the GOM. According to the limit set by the U.S. Coast Guard, it can be performed legally from 0 to 220 feet of water. There are some industry associations and operators however, that have elected to set their own limits which are less than 220 feet. In reality, once the water depth is over 120 feet, the amount of diver working time realized over a 24-hour period drops to unacceptable numbers.
Mixed gas diving has been performed in the GOM since Dan Wilson’s 1962 history making dive. Today there are few places in the world other than the GOM where it is acceptable to perform mixed gas diving. Using mixed gas will increase the diver’s bottom time over air diving; however, it also increases the amount of time between dives. This results in a decrease of the amount of diver time in the water over a 24-hour period. The U.S.C.G. allows mixed gas diving up to 300 feet.
Once the water depth is over 300 feet, saturation diving or closed bell is the only diving mode that can be legally chosen. For practical purposes, the longer a project is anticipated to last, the more cost effective saturation diving becomes. It affords the most of amount of diver working time in the water within a 24-hour period. It also has the highest associated cost per day.
Diving can be performed utilizing a variety of diving platforms. Those are lift boats, utility vessels, four point anchor vessels, anchor or spud barges and dynamic positioned vessels. The choice of the diving platform is a balance between safety, operational needs, availability and cost. A safe and efficient asset is one that can maintain position and support the diver in his efforts underwater throughout a variety of onsite conditions. To further support a project there may be specific requirements for lifting capability. These needs will narrow down assets available for the project. The ability of the diving platform to be able to lift and accurately position objects underwater could be a key factor in the diving platform selection. There is a consideration of cost differential for whichever platform is chosen.
No matter what the water depth, diving mode or diving platform used, it all comes down to one individual at the end of a hose doing the work. Having the right tool for the job is the only way to maximize the amount of work a diver can achieve in the limited amount of time he can stay in the water. Time is always working against the diver. There are purpose built tools for underwater use; it is not uncommon to see tools built specifically for a project. Time and money spent up front on tools that will ease the diver’s job is well worth the investment.
In addition to the challenge of getting the work accomplished, diving projects have the added hurdle of maintaining life support functions for the individuals performing the work. The diving industry in the GOM has a world-class safety record. There are hundreds of dives made daily in the GOM without incident. The main priority of any diving project is to return the diver to the surface unharmed. The next goal is successfully completing the scope of work. To accomplish this, proper planning is essential. Successful projects have a clear understanding of expectations and a well-designed plan to complete the scope of work.
There is one common thread between Albert Christie’s accomplishments in Summerland, Ca., Al Warriner’s design of dive equipment and salvage of the sunken construction barge in the Creole Field, Dan Wilson’s record breaking surface gas dive and Global Industries’ record breaking saturation dive - they were all planned on paper before the diver ever went in the water. Historical diving books show sketches documenting early dive equipment designs such as Christie’s, rigging plans for vessel salvage such as Warriner’s, calculations on gas mixtures for different depths such as Wilson’s and saturation system designs.
So what does a successful diving management plan look like? The water depth limits and challenges should be researched and understood. The diving mode selection should be supported with documentation showing how much work can safely be accomplished in a 24-hour period. The diving platform selection should be supported with vessel specifications and deck plans that position the crew to operate safely and efficiently in the best interest of the diver. The tooling selection should be upheld with pre-determined technical assistance and back-up equipment.
Always remember to plan your dive and dive your plan!