Section 4 Bulk storage wet and dry systems

4.1.1 The requirements for fired and unfired pressure vessels associated with the drilling plant and bulk storage vessels are to comply with the general requirements of Pt 3, Ch 8, 4 Pressure vessels and bulk storage.

4.1.2 Pressure vessels are to comply with the design requirements in Pt 3, Ch 8, 4 Pressure vessels and bulk storage.

4.1.3 Degasser and mud-gas separators are to be suitably constructed to handle the maximum design flow rate. All vented lines are to be of sufficient capacity and be vented to a safe location. Design particulars are to be submitted to LR for review.

4.1.4 Cementing units and associated high pressure pipes and manifolds are to be suitably designed and tested. If the cement unit is designed to be used as a kill unit, the components, specifications, capacities and power arrangements are to be supplied to LR for review.

4.1.5 The bulk system is to be designed to receive, store and deliver required volumes of bulk material to the mud and cementing system. Design capacities of the system are to be submitted for LR review.

4.1.6 Bulk storage vessels which penetrate watertight decks or flats are to be suitably reinforced, see Pt 3, Ch 3, 2.10 Watertight and weathertight integrity.

4.1.7 All bulk tanks, wet and dry, are to be designed for ease of cleaning and have adequate facilities for access and rescue of personnel.

4.2.1 All dry bulk tanks are to be fitted with weight or volume indicators and a high level alarm. Provision for manual measurement is to also be made available.

4.2.2 The dry bulk vessels are to be designed for ease of cleaning and have adequate facilities for access and rescue of personnel.

4.2.3 All dry bulk lines (including ventilation lines) are to be designed for minimum flow resistance, minimum possible length and as few bends as possible. Connection points for purge air will be installed at critical flow areas in the bulk lines. Vent line outlets are to be kept as far as possible from HVAC inlets and normally manned areas.

4.2.4 The bulk air supply will be designed with redundancy and is to incorporate bulk air dryers. The compressors are to be located as close to the bulk storage tanks as possible.

4.2.5 The design is to prevent inadvertent mixing of cement and other bulk material.

4.2.6 All dry bulk storage vessels are to be equipped with safety valves or bursting discs to prevent damage due to overpressure. Bursting discs may only be used for vessels located in open areas or, if fitted in conjunction with a relief line, the discharge must be led to an open area.

4.2.7 For dry bulk storage vessels in enclosed areas, testable full open safety valves which can be vented out of the area are to be used. The enclosed areas where bulk storage vessels are located are to be ventilated such that a build-up of pressure will not occur in the event of a break or leak in the air supply system.

4.3.1 Wet bulk storage tanks are to be suitably constructed with regard to the design maximum mud weight capacity of the vessel. All tanks are to be suitably equipped with equipment for preventing settling of mud.

4.3.2 The system will incorporate transfer systems with dedicated redundancy of pumps and manifolds. Sufficient by-passes with necessary valves for the liquid bulk in each storage tank are required. The systems are to be designed to transfer the relevant liquid bulk of design-specified weight and capacity to the liquid bulk tanks.

4.3.3 The design is to prevent inadvertent mixing of base oil and brine liquids.

4.3.4 High pressure mud pumps are to be fitted with pulsation dampers and relief valves set at the maximum allowable pressure of the system.

4.3.5 The mud pump relief line from the safety valve is to be self-draining and be as direct as possible with no bends and be suitably secured. The relief line after the relief valve is to be the same pressure rating as the pressure line before the relief valve. Facilities for flushing the vent lines are to be incorporated.

4.4.1 The mud mixing and storage system is to be designed with sufficient capacity and structural strength to perform all planned mud mixing and storage operations with minimum risk of spillage or release of dust or fumes.

4.4.2 The entire mixing and storage system is to be designed for safe material handling and protection for personnel and the environment.

4.5.1 The mud treatment system is to be designed to operate without any risk to personnel with regard to spillage or exposure to hazardous substances.