The pump systems (pump+driver) used in a pump station are selected based on the type of fluid or batch. The selection is of the more efficient pump systems for that batch. Less efficient pumps are avoided. When a new batch is detected, the selection is performed again for that new batch, which may result in a different combinations of pump systems for a given pump station. If variable speed pump drives are available, the efficiency at the desired speed is used for selection. The cost of energy (utilities) by pump station may alternatively or additionally be used to select the speed or combination of pump systems. The pump station and pipeline operation is optimized for efficiency of pump systems and/or cost of energy (utilities) for the different pump systems based on pipeline inventory and local utilities tariffs.

The pump systems (pump+driver) used in a pump station are selected based on the type of fluid or batch. The selection is of the more efficient pump systems for that batch. Less efficient pumps are avoided. When a new batch is detected, the selection is performed again for that new batch, which may result in a different combinations of pump systems for a given pump station. If variable speed pump drives are available, the efficiency at the desired speed is used for selection. The cost of energy (utilities) by pump station may alternatively or additionally be used to select the speed or combination of pump systems. The pump station and pipeline operation is optimized for efficiency of pump systems and/or cost of energy (utilities) for the different pump systems based on pipeline inventory and local utilities tariffs.

According to one embodiment, a system and process for the equalization of pressures of a flow stream across one or more valves is provided. A process circuit having clean non-abrasive fluid and at least one slave cylinder for transmitting pressure to a process flow stream is employed.

According to one embodiment, a system and process for the equalization of pressures of a flow stream across one or more valves is provided. A process circuit having clean non-abrasive fluid and at least one slave cylinder for transmitting pressure to a process flow stream is employed.

The present invention provides a nonresident system for depressurizing subsea apparatus and lines comprising a depressurizing tool (5) adapted for being coupled to an ROV interface (6) of a subsea apparatus, wherein the depressurizing tool (5) is coupled to an ROV (4), wherein: the ROV interface (6) comprises a first pipeline (6a) for connection to a first hydrocarbon transport line (8), a second pipeline (6b) for connection to second hydrocarbon transport line (9), and a connection mandrel (6d); and the depressurizing tool (5) comprises a suction line (5a) adapted for being connected to the first pipeline (6a) for connection to the first hydrocarbon transport line; a discharge line (5b) adapted for being connected to the second pipeline (6b) for connection to the second hydrocarbon transport line; a pump (5c); and a connector (5d) adapted for being connected to the connection mandrel (6d) of the ROV interface (6). A method is also provided for depressurizing subsea apparatus and lines, comprising the steps of: removing a blind cap (15) from an ROV interface (6) with aid of an ROV (4); coupling a depressurizing tool (5) to the ROV interface (6) of a subsea apparatus (10); suction and removal of fluid from a first hydrocarbon transport line, wherein the first hydrocarbon transport line comprises hydrate formation; and pressurizing and reinjecting the fluid into a second hydrocarbon transport line.

A method for boosting a multiphase fluid is provided. The method may include separating the multiphase fluid into a liquid phase and a gaseous phase in a separator, compressing the gaseous phase in a compressor, and discharging the compressed gaseous phase from the compressor to the discharge line. The method may also include draining the liquid phase from the separator to a liquid reservoir, passively actuating an inlet control valve to flow the liquid phase from the liquid reservoir to a liquid tank, and actively actuating an inlet actuation valve to flow a motive gas from the compressor to the liquid tank to thereby pressurize the liquid phase contained therein. The method may further include passively actuating an outlet control valve to discharge the pressurized liquid phase from the liquid tank to the discharge line, and combining the compressed gaseous phase with the pressurized liquid phase in the discharge line.

A method for boosting a multiphase fluid is provided. The method may include separating the multiphase fluid into a liquid phase and a gaseous phase in a separator, compressing the gaseous phase in a compressor, and discharging the compressed gaseous phase from the compressor to the discharge line. The method may also include draining the liquid phase from the separator to a liquid reservoir, passively actuating an inlet control valve to flow the liquid phase from the liquid reservoir to a liquid tank, and actively actuating an inlet actuation valve to flow a motive gas from the compressor to the liquid tank to thereby pressurize the liquid phase contained therein. The method may further include passively actuating an outlet control valve to discharge the pressurized liquid phase from the liquid tank to the discharge line, and combining the compressed gaseous phase with the pressurized liquid phase in the discharge line.

A multiphase flow mixed delivery device employing reciprocating driving performed by a liquid in two chambers comprises a left container (1), a right container (2), a power pump (3), a data acquisition and control system (4), a solenoid valve group, a check valve group, an inlet manifold (5), and an outlet manifold (6). A vacuum suction chamber and a compression discharging chamber alternately formed by the two containers serve as a suction chamber and a discharging chamber of a multiphase mixed flow delivery pump. After gas in a liquid-gas mixture is separated in the container, the gas is compressed by a liquid, and is discharged out of the container. The power pump constantly operates in a pure liquid working condition, thereby eliminating the issue in which a liquid with a high gas content affects the power pump. The invention requires only an ordinary water pump to achieve mixed delivery of a multiphase flow, and the ordinary water pump can even serve as a vacuum pump and a compressor for pure gas and operate continuously. Also disclosed is a multiphase flow mixed delivery method using the multiphase flow mixed delivery device employing reciprocating driving performed by a liquid in two chambers.

A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline includes an upstream portion of the pipeline supplying a flow of fluid material, a crossing portion of the pipeline receiving the flow of fluid material from the upstream portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline, the downstream portion, a pipeline pressure activated valve selectively capable of blocking the flow of fluid material from entering the crossing portion based upon a change in pressure within the crossing portion, and a fluid capacitor connected to the upstream portion configured to filter out a pressure spike in the upstream portion associated with the valve blocking the flow of fluid material.

A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline includes an upstream portion of the pipeline supplying a flow of fluid material, a crossing portion of the pipeline receiving the flow of fluid material from the upstream portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline, the downstream portion, a pipeline pressure activated valve selectively capable of blocking the flow of fluid material from entering the crossing portion based upon a change in pressure within the crossing portion, and a fluid capacitor connected to the upstream portion configured to filter out a pressure spike in the upstream portion associated with the valve blocking the flow of fluid material.