Offshore operations

Skimming tanks have already been described as the simplest form of de-oiling facility such tanks can reduce oil concentrations down to less than 200 ppm but are not suitable for offshore operations. 

The basic principles of rotary drilling defined for onshore operations are also applicable to offshore operations. The primary difference offshore is that a stable, self-contained platform must be provided for the drilling equipment. Communication with a well through possibly thousands of feet of water provides for mechanical as well as procedural differences, primarily in well control. Onshore technology can be applied to offshore operations in many instances on bottom-supported rigs, but the use of floating vessels has resulted in the development of new technology tailored to the offshore environment. 

Kruse, C. F., A Primer of Offshore Operations. Second Edition, Petroleum Extension Service, University of Texas at Austin, Austin, TX, 1985. 

Floating vessels for offshore operations offer reduced installation costs but also present additional vulnerability factors. All floating structures must ensure buoyancy integrity is maintained otherwise the vessel may sink with catastrophic results. Similarly propulsion are provided at some installations to provided position stability. All major vessels are required by insurance requirements and most marine regulations to maintain buoyancy systems and loss of position stability will impact ongoing operations. Both of these systems can therefore be considered critical support systems and must be evaluated for risk and loss control measures either thorough duplication and protection measures or a combination of both. 

The economic viability of enhanced oil recovery with C02 flooding is limited to the cases where C02 is available at low cost. This is the case for the West-Texas fields, where C02 from natural sources is available, or at the Weyburn field in Canada, where C02 can be made available from the North Dakota Gasification Plant. Unlike the situation in the United States, almost the entire European oil production is located offshore. There, enhanced oil recovery activities would be more costly, simply resulting from the larger spatial extent of production units and the entire higher costs of offshore operations. Furthermore, there are no low-cost industrial C02 sources available in the closer vicinity of the North Sea oil fields, nor is there an infrastructure for C02 transport. 

Theriot, T. Exxon-Mohil s Approach to Human Factors. 2nd International Workshop on Human Factors in Offshore Operations, 2002. 

In the oil and gas industry, the term abandonment generally refers to the activities undertaken to remove the structures used to sustain oil and gas production after the production is ceased. The structures range from a few tonnes of steel on the seabed to a complete platform constructed from around 30000 tonnes of steel framework. The task of removal requires extremely detailed and careful planning as well as substantial resources. Explosives are very efficient tools for cutting steel underwater and have been the preferred choice of many offshore operators for over 40 years. Also explosives offer the flexibility of a single controlled cut or multiple simultaneous cuts for remote and safe toppling of very large structures [129]. 

In offshore operations, exploration wells are almost always plugged and abandoned even when they strike petroleum. Their sole function is to find oil or gas and to delineate the reservoir. The operator uses this information to pick a location for a permanent production platform from which development wells will be drilled to recover as much petroleum as economically possible. In onshore operations, however, successful exploration wells also become producers. 

Captive Offshoring Used to describe a company-owned offshore operation. For example, Microsoft owns and operates significant captive offshore research and development centers in China and elsewhere that are offshore from Microsoft s U.S. home base. Also see Offshoring. ... 

We established a close rapport with colleagues in the offshore operations. Through exchanges of people, frequent meetings, a focus on science, enthusiasm, and management support, much was achieved. In local vernacular, we had a ball. 89... 

Stabilization division. Direct British "hands-on" management of the Caribbean offshore operation dates back to the 1940s, when E.D. Sassoon, Ltd. of Hong Kong — which had made its fortune... 

Jones F. V., Leuterman A. J. J., and Still I. (2000) Discharge practices and standards for offshore operations around the world. In 7th International Petroleum Environmental Conference, Albuquerque, NM, November 2000, National Energy Technology Laboratory, pp. 903-942. 

Directional drilling allows the use of one surface well and several others that radiate from the bottom of the vertical section. This means a single drill site can serve a number of wells in offshore operations or in rugged terrain. 

In offshore operations, it is desirable to discharge the produced solids overboard. Schlittler (135) described a batch process system that removed free oil from produced solids by means of a scrubber system fitted with rotating blades. The energy imparted by the blades promotes particle contact and shears the oil from the solid surfaces. The mixture of oil, solid, and water is separated by gravity in a wash tank. The cleaned solids are reported to contain less than 1 ppm oil, meeting or bettering standards for overboard discharge. 

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