Objectif The project aims to develop a subsea excavation system capable of working at water depths to approximately 200 metres with the objective of cutting and removing drill muds laden with cuttings. Such muds are discharged into the sea during oilfield drilling operations, and because of their constituency and specific gravities do not disperse with wave/current action but settle into large partially consolidated mounds on seabed areas around offshore oilfield structures. The project aims to evaluate and develop an excavation system based around the principle of a hydrostatically operated pump. The innovative aspects of the project relate to :- wide depth range,- environmental friendliness of dredging operation,- ability to lift material to surface or discharge over long horizontal distances.To date the concept of utilising a hydrostatically operated pump at water depths to - 200 m is technically and economically feasible. Hydrostatic dredge pumps have successfully operated for over 10 years in shallow water (less than - 40 m). Such operations and have proven both simple to operate and cost effective. The second phase primarily addresses the design of pressure vessels, hose system, air supply requirements and distributor arrangement of the hydrostatic pump. A dedicated suction head and deployment system will also be designed. Methods for calculating kinematic viscosity and submerged mud density have been investigated. The final phase of work developed a system design for a simple suspended prototype pump system and offshore handling package suitable for deployment from a platform or dive support vessel.The project as approved consists of two phases of work :PHASE ITask definition, equipment review, and evaluation of excavation systems and operational requirements for a dedicated subsea removal system.PHASE IIDesign and development of the technology related to a hydrostatically operated drill cuttings removal system.Because of the need to lubricate drill bits and to prevent side wall (hole) sticking during drilling operations, oilfield operations utilise bulk quantities of special muds. These muds can be constituted either using water as a base, or lower aromatics (oil based).Although such muds upon their return to surface are treated, they contain large volumes of dense, solid rock cuttings retrieved during drilling operations. Such materials are discharged onto the seabed area around platforms forming accumulations of unconsolidated and partially consolidated layers of dense material.Over the years, such material can improve additional loads on the submerged platforms orsubsea structures. To remove such material a dedicated system is required capable of operating at depths of -40 m to -200 m. Such a system needs to be able to shift large volumes of dense material, to transport it over long distances, and to entrain the hydrocarbons in the slurry to avoid damage to the marine environment.The project focuses on identifying and evaluating the technical requirements to operate a mud removal system over a wide depth range. The project identified a suitable pump technology based on the principle of hydrostatic differential to create the pumping mechanism and intends to develop such a technology for use in deeper waters. The project would result in a technical specification and design of a prototype subsea mud removal system. Programme(s) ENG-HYDROCARB 2C - Programme (EEC) of support for technological development in the hydrocarbons sector, 1986-1989 Thème(s) 1.2 - DRILLING Appel à propositions Data not available Régime de financement DEM - Demonstration contracts Coordinateur Ian Murray Engineering Ltd Contribution de l’UE Aucune donnée Adresse 85-87 Waterloo Quay AB2 1DE Aberdeen Royaume-Uni Voir sur la carte Coût total Aucune donnée
