Subsea accumulator and method of operation of same
First Claim
1. An accumulator for subsea drilling systems for the purpose of using the inherent pressure of seawater as an energy storage means, comprisinga body having a small internal bore with a bulkhead, a large internal bore, and a first annular shoulder between said small internal bore and said large internal bore, a ram having a small external diameter suitable to sealingly engage said small internal bore of said body, a small end, a large external diameter suitable for sealingly engaging said large internal bore of said body, a large end, and a second annular shoulder between said small external diameter and said large external diameter, a first cavity defined by said bulkhead, said small internal bore and said small end, a second cavity defined by said large internal bore, said small external diameter, said first annular shoulder and said second annular shoulder, such that when the seawater pressure is applied to said large end of said ram and a lower pressure than the pressure of said seawater is in either said first cavity or said second cavity, a higher pressure than said seawater pressure results in the other of said first cavity or said second cavity.
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Accused Products
Abstract
An accumulator for use in deepwater operational and control systems which uses a differential between a high pressure ambient pressure source such as sea water pressure and a low pressure source such as a chamber holding vacuum or atmospheric pressure to provide storage and delivery of hydraulic power for operation of equipment.
103 Citations
17 Claims
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1. An accumulator for subsea drilling systems for the purpose of using the inherent pressure of seawater as an energy storage means, comprising
a body having a small internal bore with a bulkhead, a large internal bore, and a first annular shoulder between said small internal bore and said large internal bore, a ram having a small external diameter suitable to sealingly engage said small internal bore of said body, a small end, a large external diameter suitable for sealingly engaging said large internal bore of said body, a large end, and a second annular shoulder between said small external diameter and said large external diameter, a first cavity defined by said bulkhead, said small internal bore and said small end, a second cavity defined by said large internal bore, said small external diameter, said first annular shoulder and said second annular shoulder, such that when the seawater pressure is applied to said large end of said ram and a lower pressure than the pressure of said seawater is in either said first cavity or said second cavity, a higher pressure than said seawater pressure results in the other of said first cavity or said second cavity.
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8. An accumulator for subsea drilling systems for the purpose of using the inherent pressure of seawater as an energy storage means, comprising
a body having a small internal bore with a first and a second annular shoulder at each end of said small internal bore, a first large internal bore on a first end closed by a first bulkhead, and a second large internal bore on a second end closed by a second bulkhead, a ram having a central portion with a small external diameter suitable to sealingly engage said small internal bore of said body, a first piston proximate a first end of said central portion of a diameter suitable to sealingly engage said first large internal bore of said body, and a second piston proximate a second end of said central portion of a diameter suitable to sealingly engage said second large internal bore of said body, a first cavity formed by said first bulkhead, said first large bore, and said first piston, a second cavity formed by said central portion of said ram, said first annular shoulder, said first large bore, and said first piston, a third cavity formed by said central portion of said ram, said second annular shoulder, said second large bore, and said second piston, a fourth cavity formed by said second bulkhead, said second large bore, and said second piston, such that said first cavity is precharged with a pressurized gas, said fourth cavity is pressurized with a low pressure or a vacuum, and seawater pressure is communicated into said third cavity, such that the pressure of fluid in said second cavity will be generally proportionate to the sum of the pressure of said pressurized gas in said first cavity plus said seawater pressure in the third chamber minus the low pressure of vacuum in said fourth chamber.
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14. The method of operating subsea equipment having one or more pistons by communicating ambient seawater pressure onto a first piston area and communicating pressure less than seawater pressure onto a second piston area,
wherein said pressure less than seawater pressure is communicated to a first piston area to move an operated device in a first direction from a first position to a second position, and then said pressure less than seawater pressure is applied to said second piston area to return said operated device back to the first position.
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15. The method of operating subsea equipment having one or more pistons by communicating ambient seawater pressure onto a first piston area and communicating pressure less than seawater pressure onto a second piston area,
wherein the pressure differential between said first piston area and said second piston area does not decline or increase due to the expansion or compression of a pressurized gas.
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16. The method of operating subsea equipment having one or more pistons by communicating ambient seawater pressure onto a first piston area and communicating pressure less than seawater pressure onto a second piston area,
wherein the pressure differential between said first piston area and said second piston area does not decline due to the cooling effect of expanding a pressurized gas or increase due to the heating effect of compressing a pressurized gas.
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17. The method of operating subsea equipment having one or more pistons by communicating ambient seawater pressure onto a first piston area and communicating pressure less than seawater pressure onto a second piston area,
wherein the pressure differential between said first piston area and said second piston area does not decline or increase due to the expansion or compression of a pressurized gas or the cooling or heating effect of expanding or compressing of a pressurized gas.
Specification