Submerged Energy and Petroleum Production System
Authors: Ellis George O. , Blumberg Randolph O. 
Published: October 2008

A subsea oil and gas production system based on use of subsea production modules using an energy source produced from a submerged turbine-powered electric generation station is described. The production and power generation station will operate at atmospheric pressure in water-tight compartmented vessel moored below the surface. The system is structurally designed to withstand major storms of hurricane force and is expected to have its greatest application in water depths of 300 ft plus and locations 20 miles or more offshore.

The power station utilizes a shaft for purposes of air intake, exhaust, access passageway support for a heliport, and dock. The shaft is a rigid cylindrical structure extending upward from the submerged station to a point several feet above the water level. The electrical power is conducted through armored cables to seafloor mounted oil and gas production equipment modules. The production modules which contain equipment, such as compressors, pipeline pumps, heaters and dehydrators, are all of modular construction for simplicity of removing for major repairs or relocation to another producing area. Existing technology and state-of-the-art are used essentially throughout the system to minimize the problems as so dared-with completely new designs. This system is estimated to be considerably more economical than fixed platform systems for deep water applications, and is less susceptible to hurricane damage.

INTRODUCTION

The capacity for the production of substantial quantities of offshore oil and gas has only recently been achieved. A few years ago production of gas from wells in deep waters on the continental shelf of the Gulf of Mexico was not considered to be economical. With increasing demands for hydrocarbon energy from natural gas, producing companies have been proposing and developing gas production from areas out to350-ft mean water depths in the open waters of the Gulf. The production of gas and oil from such moderately deep water areas currently requires the installation of larged fixed production platforms to support the required production equipment.

Although platform designs have been proposed for water depths out to 1,000-ft depths, none of these deep water structures has as yet been installed. In fact, the multimillion dollar cost of production platforms in water depths of 350 ft already represent a drastic increase in platform cost over similar platforms installed in water depths of 100 to 200 ft.

Just as there is a practical limit to the height a land-based building can be constructed, there is also a practical limit to the water depth in which a conventional fixed platform can be constructed. At this limit, it is necessary to either resort to floating-type equipment or subsea equipment in order to develop the resources from these deep water areas.

Since environmental forces at the water surface can be extremely severe at times, the approach to using submerged subsea systems offers considerable promise. Furthermore a system, once developed, for deeper water may possibly compete economically in shallower water areas where fixed platforms have historically been used.