초록 ▼

A separation method and apparatus are disclosed having particular application for effecting removal of sand from a production wellstream, enhancing the quality of recovered oil, gas and water output streams (12, 13, 14) and reducing erosion caused by entrained sand. The wellstream is passed initial

A separation method and apparatus are disclosed having particular application for effecting removal of sand from a production wellstream, enhancing the quality of recovered oil, gas and water output streams (12, 13, 14) and reducing erosion caused by entrained sand. The wellstream is passed initially through a cyclone separator (4' ) which separates substantially all the water and sand as underflow and substantially all the oil and gas as overflow. A gravity separator ( 11) separates the overflow from the cyclone separator (4') into oil, gas and water, and a further cyclone separator (17) separates the underflow from the first cyclone separator (4') into water and sand.

대표청구항 ▼

The invention claimed is: 1. A method of recovering production fluid from a production well, which fluid contains a multi-phase mixture comprising oil and water and particles entrained therein, said method comprising: passing the production fluid from the well; then a first separating step of separ

The invention claimed is: 1. A method of recovering production fluid from a production well, which fluid contains a multi-phase mixture comprising oil and water and particles entrained therein, said method comprising: passing the production fluid from the well; then a first separating step of separating the production fluid passed from the well, by cyclonic separation at a separating point between the densities of the oil and water into a first portion that is rich in water and particles and a second portion that is rich in oil; a second separating step of separating the first portion of fluid into a third portion that has a higher water-to-particle ratio than said first portion and a fourth portion that has a higher particle-to-water ratio than said first portion; and a third separating step of separating water from the second fluid portion. 2. A method according to claim 1, wherein the production fluid also contains gas and further comprising separating the gas from the production fluid after the step of passing the production fluid from the well and before the first separating step. 3. A method according to claim 1, wherein the second step of separating is by cyclonic separation at a separating point between the densities of the particles and water, and particles in the fourth portion of fluid are accumulated to separate them from water in the fourth portion. 4. A method according to claim 1, wherein the third step of separating is by gravity separation. 5. A method according to claim 1, wherein the first portion of fluid contains water and substantially no oil and wherein the second portion of fluid contains oil and a minor proportion of water, and further comprising combining the third portion of fluid with the water separated from the second fluid portion. 6. A method according to claim 1, wherein the first portion of water contains water and a minor proportion of oil and the second portion of fluid contains oil and substantially no water, and wherein the third portion of fluid is combined with the second portion of fluid before the third step of separating. 7. A method according to claim 1, wherein the first portion of fluid contains water and a minor portion of oil and the second portion of fluid contains oil and substantially no water, and wherein the water separated by the second separating step contains a lesser portion of oil than said first portion. 8. A method according to claim 1, further comprising measuring the water or oil content respectively of the first or second portion of fluid, and controlling a parameter of the second portion of the fluid to increase the water or oil content of the first or second portions, respectively. 9. A method according to claim 8, wherein said parameter is the flow rate of the second portion of the fluid. 10. A method according to claim 1 wherein the step of passing comprises passing the fluid directly from the well to apparatus for performing the first separating step. 11. A production fluid recovery installation comprising: a source of production fluid comprising oil and water and particles entrained therein; a first separator connected to the source externally of the well for receiving the production fluid and for cyclonically separating the production fluid, at a separation point between the densities of the oil and water, into a first portion that is rich in water and particles and a second portion that is rich in oil; a second separator for separating the first portion of the fluid into water and particles; and a third separator for separating any water from the oil in the second fluid portion. 12. An installation according to claim 11, wherein the production fluid also contains gas and further comprising means for separating the gas from the production fluid before the production fluid is received by the first separator. 13. An installation according to claim 11, further comprising means for combining the water separated by the second separator with the water separated by the third separator. 14. An installation according to claim 11, further comprising means for combining the water separated in the second separator with the second portion of fluid separated in the first separator, before the second portion of fluid enters the third separator. 15. An installation according to claim 11, further comprising a measuring device for measuring the water or oil contents respectively of the first or second portions of fluid, and means for controlling the flow rate of the second portion of the fluid in response to the measured values. 16. An installation according to claim 11, further comprising a manifold connected to the source and adapted to receive the production fluid from the source. 17. An installation according to claim 11, wherein the production fluid is passed directly from the well to the first separator.