Title of Invention	METHOD FOR DELIVERING MULTI-PHASE MIXTURES AND PUMP INSTALLATION
Abstract	The aim of the invention is to improve delivery of the multi-phase especially hydrocarbons from a well and to limit the free gas volume. According to the invention, a partial liquid flow (13) is branched off on the pressure side from the main supply flow and is delivered on the high-pressure side to at least one jet pump (2) that is disposed on the suction side (1) as an auxiliary delivery device. The pump installation comprises a feed line (7) linking the pressure chamber of the displacement pump (1) with the high pressure side of at least one jet pump (2), said jet pump (2) being disposed on the suction side in the direction of delivery of the displacement pump (1).

Title of Invention

METHOD FOR DELIVERING MULTI-PHASE MIXTURES AND PUMP INSTALLATION

Abstract

The aim of the invention is to improve delivery of the multi-phase especially hydrocarbons from a well and to limit the free gas volume. According to the invention, a partial liquid flow (13) is branched off on the pressure side from the main supply flow and is delivered on the high-pressure side to at least one jet pump (2) that is disposed on the suction side (1) as an auxiliary delivery device. The pump installation comprises a feed line (7) linking the pressure chamber of the displacement pump (1) with the high pressure side of at least one jet pump (2), said jet pump (2) being disposed on the suction side in the direction of delivery of the displacement pump (1).

Full Text	Method for Delivering Multi-phase Mixtures and Pump Installation The invention relates to a method for delivering multi-phase mixtures, in particular hydrocarbons from a well, with a displacement pump through which the multi-phase mixture is pumped, and a pump installation with a displacement pump for delivering multi-phase mixtures with a suction line and a pressure chamber, whereby the suction line discharges in particular into a well. Hydrocarbon delivery with multi-phase pumps installed on the surface, generally in the vicinity of the well, is an economical, sufficiently reliable and efficient technology for delivery from weak springs and for increasing the degree of deoiling. Multi-phase pumps are known per se, e.g., from EP 0 699 276 A1, to which reference is made in its entirety, and the disclosure of which is incorporated into the application. Pressure reductions on the solar head to approx. 2 - 5 bar are typical for hydrocarbon delivery, e.g., crude oil and natural gas delivery; lower head pressures are generally not very economical because of the volume expansion of the gas proportion and the increasing construction expenditure resulting therefrom. GB 2264147 A1 relates to a multi-phase pumping arrangement used in a method for pumping a liquid/gaseous phase mixture from an underground reservoir to a process plant, in which the pump arrangement is positionable in a flow line running between the reservoir and the process plant. A gas/liquid separator has an intake of liquid/gaseous phase product via an input line. The gas/liquid separator receives a low pressure multi-phase mixture from the flowing well and separated liquid is discharged via a discharge line wherein separated free gas exit via an exit line. A standard liquid duty pump boost the pressure of the liquids from the discharge line and discharges this into an output line. A jet pump is arranged downstream of the liquid pump and uses the high pressure liquid supply as the power fluid which undergoes pressure reduction, whereby gas from a low pressure line is ingested into the jet pump. The co-mingled gas/liquids are than discharged to a discharge pipe at a pressure significantly greater than the pressure in supply line. This pumping arrangement needs a separate gas/liquid separator and the fluid pump is not designed for delivering a multi-phase mixture. No separation of liquid phase and gas phase is carried out in the displacement pump. No partial liquid flow is split off on the pressure side of the liquid pump. No feed line connects the pressure chamber of the liquid pump with the high pressure side of at least one ejector pump arranged on the suction side in the delivery direction of the liquid pump and guides the separated liquid phase to the ejector pump. US 2003/0085036 A1 discloses a multi-phase pump system having a multiphase pump, a pressure compensated pump and a power unit. The multi-phase pump is designed as a piston pump having two pairs of driving cylinders placed in line with the respective vertically disposed plungers. The pressure compensated pump supplies hydraulic fluid to the cylinders to control the movement of the plungers. A fluid circuit connects a wellbore outlet to a wellbore inlet. From the multi-phase pump the fluid from the wellbore is guided to a two-phase-separator to separate the gas phase from the liquid phase. The fluid phase is immediately discharged into a pipeline wherein the pressurized gas phase is guided through the wellbore outlet into a measuring device. In the measuring device the amount of pressurized gas guided to the intake is controlled wherein surplus gas is pumped through a gas pipeline. There is no indication that the separation of gas phase and liquid phase is carried out in the displacement pump and that a partial liquid flow is split off on the pressure side from the main delivery flow and guided to the high pressure side of at least one ejector pump arranged on the suction side of the displacement pump as an auxiliary delivery device. In contrary, US 2003/0085036 A1 teaches that the entire liquid phase is sent directly into the pipeline. US 4,718,486 discloses a portable jet pump system with a pump lowered down hole raised with coiled pipe and return line, having a pump system, in which water is pumped by a plunger pump to a jet pump lowered down hole. The suction line of the plunger pump is not directly connected to the wellbore but to a retention/separation tank and an oil recovery system. The recovered oil is stored in an oil tank and the separated water is guided to a water recovery system from which it is directed to the plunger pump. The plunger pump as the displacement pump is not delivering multi-phase mixtures but water. No separation of gas phase and liquid phase is carried out in the displacement pump. No partial liquid flow is split off on the pressure side from the main delivery flow and guided to the high pressure side of at least one ejector pump arranged on the suction side of the displacement pump as an auxiliary delivery device. The jet pump arranged down hole is the only delivery device. No feed line connects the pressure chamber of the displacement pump with the high pressure side of at least one ejector pump arranged on the suction side in the delivery direction of the displacement pump and guides the separated phase to the ejector pump. The plunger pump is designed as a liquid pump not as a multi-phase pump. On the basis of this prior art, it is the object of the invention to provide a method and a pump installation with which conveying the multi-phase mixture is improved and, at the same time, the required construction expenditure for the pump installation is limited. According to the invention, this object is attained in that a separation of gas phase and liquid phase is carried out in the displacement pump in that partial liquid flow is split off on the pressure side from the main delivery flow and guided to the high-pressure side of at least one ejector pump arranged on the suction side of the displacement pump as an auxiliary delivery device or in that a feed line connects the pressure chamber of the displacement pump with the high pressure side of at least one ejector pump and the ejector pump is arranged on the inlet side in the delivery direction of the displacement pump. The pressure liquid used to drive the ejector pump circulates between the ejector pump and the displacement pump, in particular embodied as a multi-phase pump, without any permanent contamination of the delivery mixture. In addition, the energy supply of the ejector pump is ensured without an external energy source, in particular a hydraulic energy source, having to be provided. By means of a suitable design of the ejector pump it can be achieved that the displacement pump is fed with a moderate prepressure of, e.g., 2 bar, so that conveying the multi-phase mixture is improved and the free gas volume is limited at the same time. This can result in a reduction of the construction expenditure of the displacement pump, which reduces the overall costs. The ejector pump is advantageously arranged in or on the well, if the multi-phase mixture is delivered from a hydrocarbon source, in order to facilitate the intake of the hydrocarbons. Alternatively, it is possible for the ejector pump to be arranged within the suction line. Multi-phase mixtures are characterized by a high variability in their composition, whereby this is a multi-component mixture that can be present in several phases. The composition can change from almost 100% liquid phase to almost 100% gas phase, whereby there can also be large proportions of solids in a multi-phase mixture. In order to achieve a sufficient cooling and sealing of the displacement pump, it is provided that a separation of gas phase and liquid phase is carried out in the displacement pump and the partial liquid flow to the ejector pump is split off from the separated liquid phase. For operating the ejector pump, a liquid is thus used that has only a low gas proportion left and corresponds to the liquid phase of the delivered product. Therefore, there is no change or contamination of the delivery product through the use of the split-off partial liquid flow as an energy source for the ejector pump, and the displacement pump is always supplied on the suction side with a liquid proportion, so that there is a sufficient lubrication, cooling and sealing of the displacement pump. A further development of the invention provides that a partial volume flow of the separated liquid phase is fed to the suction side of the displacement pump via a short-circuited line in a portioned manner, so that thus the supply does not take place exclusively via the ejector pump, but via a short-circuited line arranged preferably within the displacement pump housing, which renders it possible to reduce the danger of the displacement pump running dry. A further development of the invention provides that after the partial liquid flow has been split off, this flow is guided through an additional separator for dividing gas phase from liquid phase, if the separation within the displacement pump has not been sufficient. The additional separator ensures that a liquid phase largely freed of the gas phase is fed to the ejector pump as a pressure liquid and energy source. In order to provide a sufficiently high pressure level, in particular a constant pressure level, a booster pump is provided between the displacement pump and the ejector pump, which booster pump increases the delivery pressure. The pump installation according to the invention provides that a feed line connects the pressure chamber of the displacement pump with the high-pressure side of at least one ejector pump, whereby the ejector pump is arranged on one side in the delivery direction of the displacement pump, in order to feed the displacement pump with a moderate prepressure. A partial liquid flow is thus guided from the pressure side of the displacement pump to the high-pressure side of one or more ejector pumps that are used as auxiliary delivery devices, which causes a particularly economical pressure increase on the suction side. As opposed to active components for increasing the prepressure, in which mechanical parts cause a pressure increase, e.g., in the form of down-hole pump technologies, such as beam pump, ESP, PCP or SSP, ejector pumps are built in an extremely simple manner and do not have any moving members. Not using mechanical components is advantageous in particular on account of the sometimes high abrasive properties of the delivered multi-phase mixture. As a result of the low maintenance expenditure, the installations are more reliable and cost-efficient, especially since accessibility is limited in the area of a well and a repair is very complex This causes long downtimes and economic efficiency problems for the operators of the installation. Advantageously, separation devices for dividing gas phase from liquid phase are embodied within the displacement pump housing in the pressure chamber, through which the gas phase of the multi-phase mixture is separated from the liquid phase, and only the liquid phase is used to drive the ejector pump. In order to ensure that a certain liquid circulation is present for sealing, lubricating and cooling the displacement pump with a particularly long embodiment of the feed line, a short-circuited line is provided from the pressure-chamber side to the suction side of the displacement pump for the portioned feeding of the separated liquid phase. For the improved division of liquid phase from gas phase, an additional separator is provided in the feed line, from which additional separator a return line of the separated gas phase leads to the pressure line of the displacement pump, so that the gas phase can be carried off together with the other delivery products for further processing. A booster pump is arranged in the feed line, so that the separated liquid phase has an increased energy content. It has proven advantageous for the displacement pump to be embodied as a screw pump, as screw pumps reliably deliver multi-phase mixtures, in particular with a high proportion of abrasive substances and highly fluctuating gas proportions, and offer advantages in terms of availability. For assembly reasons it is advantageous to arrange the ejector pump in or on the well at the end of the suction line; alternatively it is possible to arrange the ejector pump in a different location, e.g., in the suction line closer to the displacement pump or also in a well distant from the suction line. An exemplary embodiment of the invention will be explained below on the basis of the only figure which shows the structure of a pump installation in principle. The core of the pump installation is a displacement pump 1 which is provided as a multi-phase pump and advantageously embodied as a screw pump. A suction line 10 is arranged on the suction side, which line discharges into a well 3. An ejector pump 2 is arranged at the end of the suction line 10 within the well, which ejector pump is oriented such that the high-pressure side of the ejector pump 2 faces in the direction of the suction side of the displacement pump 1, in order to load the displacement pump 1 with a prepressure. The ejector pump 2, preferably embodied as a jet pump, is fed via a partial liquid flow 13 split off on the pressure side from the displacement pump 1. The partial liquid flow 13 is guided to the high-pressure side of the ejector pump 2 via a feed line 7. The partial liquid flow 13 is split off from a separated multi-phase mixture, whereby a separation of the liquid phase and the gas phase takes place within the displacement pump. A predetermined amount of liquid phase is split off on the pressure side from the displacement pump 1, the other delivery product is guided through a pressure line 11 to further processing. An additional separator 4 is interposed for the further separation of gas phase and liquid phase of the multi-phase mixture, from which additional separator a return line 14 leads to the pressure line 11, whereby the liquid phase not required or the additional separated gas phase is guided to the pressure line 11. A booster pump 5 is optionally provided in the feed line 7 in order to increase the energy level of the pressure liquid for the ejector pump 2. A short-circuited line 15 is also optionally provided, via which a partial flow from the separated liquid is fed to the displacement pump 1 on the suction side, in order to always ensure a sufficient cooling and lubrication. The short-circuited line 15 can also be embodied within the displacement pump housing. An auxiliary delivery device is made available through the circulation of a partial liquid flow within the pump installation, so that the displacement pump can better convey the multi-phase mixture as a result of the existing prepressure, whereby the volume expansion of the gas proportion is limited and the increased construction expenditure resulting therefrom is avoided. The simple structure of the ejector pump without moving members reduces the constructional expenditure and prevents downtimes on account of repairs resulting from the wear of mechanical components. In addition, no external energy source, mixed with the delivery product, is used as a pressure liquid, which can be an impediment with the subsequent processing of the delivery product. Furthermore, no separate pressure liquid is available in many cases, so that a constant usability of the pump installation is ensured. Naturally, several ejector pumps 2 can be fed by one displacement pump 1. WE CLAIM : 1. Method for delivering multi-phase mixtures, in particular hydrocarbons from a well, with a displacement pump (1) through which the multi-phase mixture is pumped and a separation device (1, 4) in which the gas phase is separated from a liquid phase, characterized in that a separation of gas phase and liquid phase is carried out in the displacement pump (1) and that a partial liquid flow (13) is split off on the pressure side from the main delivery flow and guided to the high- pressure side of at least one ejector pump (2) arranges on the suction side of the displacement pump (1) as an auxiliary delivery device. 2. Method according to claim 1, characterized in that the ejector pump (2) is arranged in or on the well (3). 3. Method according to claim 2, characterized in that a partial volume flow of the separated liquid phase is fed in a portioned manner to the suction side of the displacement pump (1) via a short-circuited line (15). 4. Method according to one of the preceding claims, characterized in that after the partial liquid flow (3) has been split off, this flow is guided through an additional separator (4) for dividing gas phase from liquid phase. 5. Method according to one of the preceding claims, characterized in that the delivery pressure is increased between the displacement pump (1) and the ejector pump (2) by a booster pump (5). 6. Pump installation with a displacement pump (1) for delivering multi-phase mixtures with a pump housing in which a pressure chamber is embodied, whereby separation devices are embodied within the displacement pump housing to divide gas phase from liquid phase in the pressure chamber, and a suction line (10) is present, whereby the suction line 910) discharges in particular into a well (30, characterized in that: a feed line (7) connects the pressure chamber of the displacement pump (1) with the high-pressure side of at least one ejector pump (2) arranged on the suction side in the delivery direction of the displacement pump (1) and guides the separated liquid phase to the ejector pump (2). 7. Pump installation according to claim 7, characterized in that the ejector pump (2) is arranged in the area of discharge of the suction line (10) into the well (3) in the delivery direction of the displacement pump (1). 8. Pump installation according to claim 7 or 8, characterized in that a short-circulated line (15) leads from the pressure-chamber side to the suction side of the displacement pump (1) for the portioned feeding of the separated liquid phase. 9. Pump installation according to one of claims 6 through 8, characterized in that an additional separator (4) is arranged in the feed line (7) for dividing the liquid phase from the gas phase. 10. Pump installation according to claim 9, characterized in that a return line (14) leads from the additional separator (4) to the pressure line (11) of the displacement pump (1). 11. Pump installation according to one of claims 6 through 10, characterized ion that a booster pump (5) is arranged in the feed line (7). 12. Pump installation according to one of claims 6 through 11, characterized in that the displacement pump (1) is embodied as a screw pump. 13. Pump installation according to one of claims 6 through 12, characterized in that the ejector pump (2) is arranged in or on the well (3), in particular at the end of the suction line (10). The aim of the invention is to improve delivery of the multi-phase especially hydrocarbons from a well and to limit the free gas volume. According to the invention, a partial liquid flow (13) is branched off on the pressure side from the main supply flow and is delivered on the high-pressure side to at least one jet pump (2) that is disposed on the suction side (1) as an auxiliary delivery device. The pump installation comprises a feed line (7) linking the pressure chamber of the displacement pump (1) with the high pressure side of at least one jet pump (2), said jet pump (2) being disposed on the suction side in the direction of delivery of the displacement pump (1).

Full Text

Method for Delivering Multi-phase Mixtures and Pump Installation
The invention relates to a method for delivering multi-phase mixtures, in particular hydrocarbons from a well, with a displacement pump through which the multi-phase mixture is pumped, and a pump installation with a displacement pump for delivering multi-phase mixtures with a suction line and a pressure chamber, whereby the suction line discharges in particular into a well.
Hydrocarbon delivery with multi-phase pumps installed on the surface, generally in the vicinity of the well, is an economical, sufficiently reliable and efficient technology for delivery from weak springs and for increasing the degree of deoiling. Multi-phase pumps are known per se, e.g., from EP 0 699 276 A1, to which reference is made in its entirety, and the disclosure of which is incorporated into the application. Pressure reductions on the solar head to approx. 2 - 5 bar are typical for hydrocarbon delivery, e.g., crude oil and natural gas delivery; lower head pressures are generally not very economical because of the volume expansion of the gas proportion and the increasing construction expenditure resulting therefrom.
GB 2264147 A1 relates to a multi-phase pumping arrangement used in a method for pumping a liquid/gaseous phase mixture from an underground reservoir to a process plant, in which the pump arrangement is positionable in a flow line running between the reservoir and the process plant. A gas/liquid separator has an intake of liquid/gaseous phase product via an input line. The gas/liquid separator receives a low pressure multi-phase mixture from the flowing well and separated liquid is discharged via a discharge line wherein separated free gas exit via an exit line. A standard liquid duty pump boost the pressure of the liquids from the discharge line and discharges this into an output line. A jet pump is arranged downstream of the liquid pump and uses the high pressure liquid supply as the power fluid which undergoes pressure reduction, whereby gas from a low pressure line is ingested into the jet pump. The co-mingled gas/liquids are than discharged to a discharge pipe at a pressure significantly greater than the pressure in supply line. This pumping arrangement needs a separate gas/liquid separator and the fluid pump is not

designed for delivering a multi-phase mixture. No separation of liquid phase and gas phase is carried out in the displacement pump. No partial liquid flow is split off on the pressure side of the liquid pump. No feed line connects the pressure chamber of the liquid pump with the high pressure side of at least one ejector pump arranged on the suction side in the delivery direction of the liquid pump and guides the separated liquid phase to the ejector pump.
US 2003/0085036 A1 discloses a multi-phase pump system having a multiphase pump, a pressure compensated pump and a power unit. The multi-phase pump is designed as a piston pump having two pairs of driving cylinders placed in line with the respective vertically disposed plungers. The pressure compensated pump supplies hydraulic fluid to the cylinders to control the movement of the plungers. A fluid circuit connects a wellbore outlet to a wellbore inlet. From the multi-phase pump the fluid from the wellbore is guided to a two-phase-separator to separate the gas phase from the liquid phase. The fluid phase is immediately discharged into a pipeline wherein the pressurized gas phase is guided through the wellbore outlet into a measuring device. In the measuring device the amount of pressurized gas guided to the intake is controlled wherein surplus gas is pumped through a gas pipeline. There is no indication that the separation of gas phase and liquid phase is carried out in the displacement pump and that a partial liquid flow is split off on the pressure side from the main delivery flow and guided to the high pressure side of at least one ejector pump arranged on the suction side of the displacement pump as an auxiliary delivery device. In contrary, US 2003/0085036 A1 teaches that the entire liquid phase is sent directly into the pipeline.
US 4,718,486 discloses a portable jet pump system with a pump lowered down hole raised with coiled pipe and return line, having a pump system, in which water is pumped by a plunger pump to a jet pump lowered down hole. The suction line of the plunger pump is not directly connected to the wellbore but to a retention/separation tank and an oil recovery system. The recovered oil is stored in an oil tank and the separated water is guided to a water recovery

system from which it is directed to the plunger pump. The plunger pump as the displacement pump is not delivering multi-phase mixtures but water. No separation of gas phase and liquid phase is carried out in the displacement pump. No partial liquid flow is split off on the pressure side from the main delivery flow and guided to the high pressure side of at least one ejector pump arranged on the suction side of the displacement pump as an auxiliary delivery device. The jet pump arranged down hole is the only delivery device. No feed line connects the pressure chamber of the displacement pump with the high pressure side of at least one ejector pump arranged on the suction side in the delivery direction of the displacement pump and guides the separated phase to the ejector pump. The plunger pump is designed as a liquid pump not as a multi-phase pump.
On the basis of this prior art, it is the object of the invention to provide a method and a pump installation with which conveying the multi-phase mixture is improved and, at the same time, the required construction expenditure for the pump installation is limited.
According to the invention, this object is attained in that a separation of gas phase and liquid phase is carried out in the displacement pump in that partial liquid flow is split off on the pressure side from the main delivery flow and guided to the high-pressure side of at least one ejector pump arranged on the suction side of the displacement pump as an auxiliary delivery device or in that a feed line connects the pressure chamber of the displacement pump with the high pressure side of at least one ejector pump and the ejector pump is arranged on the inlet side in the delivery direction of the displacement pump.

The pressure liquid used to drive the ejector pump circulates between the ejector pump and the displacement pump, in particular embodied as a multi-phase pump, without any permanent contamination of the delivery mixture. In addition, the energy supply of the ejector pump is ensured without an external energy source, in particular a hydraulic energy source, having to be provided.
By means of a suitable design of the ejector pump it can be achieved that the displacement pump is fed with a moderate prepressure of, e.g., 2 bar, so that conveying the multi-phase mixture is improved and the free gas volume is limited at the same time. This can result in a reduction of the construction expenditure of the displacement pump, which reduces the overall costs.
The ejector pump is advantageously arranged in or on the well, if the multi-phase mixture is delivered from a hydrocarbon source, in order to facilitate the intake of the hydrocarbons. Alternatively, it is possible for the ejector pump to be arranged within the suction line.
Multi-phase mixtures are characterized by a high variability in their composition, whereby this is a multi-component mixture that can be present in several phases. The composition can change from almost 100% liquid phase to almost 100% gas phase, whereby there can also be large proportions of solids in a multi-phase mixture. In order to achieve a sufficient cooling and sealing of the displacement pump, it is provided that a separation of gas phase and liquid phase is carried out in the displacement pump and the partial liquid flow to the ejector pump is split off from the separated liquid phase. For operating the ejector pump, a liquid is thus used that has only a low gas proportion left and corresponds to the liquid phase of the delivered product. Therefore, there is no change or contamination of the delivery product through the use of the split-off partial liquid flow as an energy source for the ejector pump, and the displacement pump is always supplied on the suction side with a liquid proportion, so that there is a sufficient lubrication, cooling and sealing of the displacement pump.

A further development of the invention provides that a partial volume flow of the separated liquid phase is fed to the suction side of the displacement pump via a short-circuited line in a portioned manner, so that thus the supply does not take place exclusively via the ejector pump, but via a short-circuited line arranged preferably within the displacement pump housing, which renders it possible to reduce the danger of the displacement pump running dry.
A further development of the invention provides that after the partial liquid flow has been split off, this flow is guided through an additional separator for dividing gas phase from liquid phase, if the separation within the displacement pump has not been sufficient. The additional separator ensures that a liquid phase largely freed of the gas phase is fed to the ejector pump as a pressure liquid and energy source.
In order to provide a sufficiently high pressure level, in particular a constant pressure level, a booster pump is provided between the displacement pump and the ejector pump, which booster pump increases the delivery pressure.
The pump installation according to the invention provides that a feed line
connects the pressure chamber of the displacement pump with the high-pressure
side of at least one ejector pump, whereby the ejector pump is arranged on one
side in the delivery direction of the displacement pump, in order to feed the
displacement pump with a moderate prepressure. A partial liquid flow is thus
guided from the pressure side of the displacement pump to the high-pressure
side of one or more ejector pumps that are used as auxiliary delivery devices,
which causes a particularly economical pressure increase on the suction side.
As opposed to active components for increasing the prepressure, in which
mechanical parts cause a pressure increase, e.g., in the form of down-hole pump
technologies, such as beam pump, ESP, PCP or SSP, ejector pumps are built in
an extremely simple manner and do not have any moving members. Not using
mechanical components is advantageous in particular on account of the
sometimes high abrasive properties of the delivered multi-phase mixture. As a

result of the low maintenance expenditure, the installations are more reliable and cost-efficient, especially since accessibility is limited in the area of a well and a repair is very complex This causes long downtimes and economic efficiency problems for the operators of the installation. Advantageously, separation devices for dividing gas phase from liquid phase are embodied within the displacement pump housing in the pressure chamber, through which the gas phase of the multi-phase mixture is separated from the liquid phase, and only the liquid phase is used to drive the ejector pump.
In order to ensure that a certain liquid circulation is present for sealing, lubricating and cooling the displacement pump with a particularly long embodiment of the feed line, a short-circuited line is provided from the pressure-chamber side to the suction side of the displacement pump for the portioned feeding of the separated liquid phase.
For the improved division of liquid phase from gas phase, an additional separator is provided in the feed line, from which additional separator a return line of the separated gas phase leads to the pressure line of the displacement pump, so that the gas phase can be carried off together with the other delivery products for further processing.
A booster pump is arranged in the feed line, so that the separated liquid phase has an increased energy content.
It has proven advantageous for the displacement pump to be embodied as a screw pump, as screw pumps reliably deliver multi-phase mixtures, in particular with a high proportion of abrasive substances and highly fluctuating gas proportions, and offer advantages in terms of availability.
For assembly reasons it is advantageous to arrange the ejector pump in or on the well at the end of the suction line; alternatively it is possible to arrange the ejector pump in a different location, e.g., in the suction line closer to the displacement pump or also in a well distant from the suction line.

An exemplary embodiment of the invention will be explained below on the basis of the only figure which shows the structure of a pump installation in principle.
The core of the pump installation is a displacement pump 1 which is provided as a multi-phase pump and advantageously embodied as a screw pump. A suction line 10 is arranged on the suction side, which line discharges into a well 3. An ejector pump 2 is arranged at the end of the suction line 10 within the well, which ejector pump is oriented such that the high-pressure side of the ejector pump 2 faces in the direction of the suction side of the displacement pump 1, in order to load the displacement pump 1 with a prepressure.
The ejector pump 2, preferably embodied as a jet pump, is fed via a partial liquid flow 13 split off on the pressure side from the displacement pump 1. The partial liquid flow 13 is guided to the high-pressure side of the ejector pump 2 via a feed line 7.
The partial liquid flow 13 is split off from a separated multi-phase mixture, whereby a separation of the liquid phase and the gas phase takes place within the displacement pump. A predetermined amount of liquid phase is split off on the pressure side from the displacement pump 1, the other delivery product is guided through a pressure line 11 to further processing. An additional separator 4 is interposed for the further separation of gas phase and liquid phase of the multi-phase mixture, from which additional separator a return line 14 leads to the pressure line 11, whereby the liquid phase not required or the additional separated gas phase is guided to the pressure line 11.
A booster pump 5 is optionally provided in the feed line 7 in order to increase the energy level of the pressure liquid for the ejector pump 2.
A short-circuited line 15 is also optionally provided, via which a partial flow from the separated liquid is fed to the displacement pump 1 on the suction side, in order to always ensure a sufficient cooling and lubrication. The short-circuited line 15 can also be embodied within the displacement pump housing.

An auxiliary delivery device is made available through the circulation of a partial liquid flow within the pump installation, so that the displacement pump can better convey the multi-phase mixture as a result of the existing prepressure, whereby the volume expansion of the gas proportion is limited and the increased construction expenditure resulting therefrom is avoided. The simple structure of the ejector pump without moving members reduces the constructional expenditure and prevents downtimes on account of repairs resulting from the wear of mechanical components. In addition, no external energy source, mixed with the delivery product, is used as a pressure liquid, which can be an impediment with the subsequent processing of the delivery product. Furthermore, no separate pressure liquid is available in many cases, so that a constant usability of the pump installation is ensured.
Naturally, several ejector pumps 2 can be fed by one displacement pump 1.

WE CLAIM :
1. Method for delivering multi-phase mixtures, in particular
hydrocarbons from a well, with a displacement pump (1) through which
the multi-phase mixture is pumped and a separation device (1, 4) in
which the gas phase is separated from a liquid phase, characterized in
that a separation of gas phase and liquid phase is carried out in the
displacement pump (1) and that a partial liquid flow (13) is split off on
the pressure side from the main delivery flow and guided to the high-
pressure side of at least one ejector pump (2) arranges on the suction
side of the displacement pump (1) as an auxiliary delivery device.
2. Method according to claim 1, characterized in that the ejector pump (2) is arranged in or on the well (3).
3. Method according to claim 2, characterized in that a partial volume flow of the separated liquid phase is fed in a portioned manner to the suction side of the displacement pump (1) via a short-circuited line (15).
4. Method according to one of the preceding claims, characterized in that after the partial liquid flow (3) has been split off, this flow is guided through an additional separator (4) for dividing gas phase from liquid phase.

5. Method according to one of the preceding claims, characterized in
that the delivery pressure is increased between the displacement
pump (1) and the ejector pump (2) by a booster pump (5).
6. Pump installation with a displacement pump (1) for delivering
multi-phase mixtures with a pump housing in which a pressure
chamber is embodied, whereby separation devices are embodied
within the displacement pump housing to divide gas phase from liquid
phase in the pressure chamber, and a suction line (10) is present,
whereby the suction line 910) discharges in particular into a well (30,
characterized in that: a feed line (7) connects the pressure chamber of
the displacement pump (1) with the high-pressure side of at least one
ejector pump (2) arranged on the suction side in the delivery direction
of the displacement pump (1) and guides the separated liquid phase
to the ejector pump (2).
7. Pump installation according to claim 7, characterized in that the ejector pump (2) is arranged in the area of discharge of the suction line (10) into the well (3) in the delivery direction of the displacement pump (1).
8. Pump installation according to claim 7 or 8, characterized in that a short-circulated line (15) leads from the pressure-chamber side to the suction side of the displacement pump (1) for the portioned feeding of the separated liquid phase.

9. Pump installation according to one of claims 6 through 8, characterized in that an additional separator (4) is arranged in the feed line (7) for dividing the liquid phase from the gas phase.
10. Pump installation according to claim 9, characterized in that a return line (14) leads from the additional separator (4) to the pressure line (11) of the displacement pump (1).

11. Pump installation according to one of claims 6 through 10, characterized ion that a booster pump (5) is arranged in the feed line (7).
12. Pump installation according to one of claims 6 through 11, characterized in that the displacement pump (1) is embodied as a screw pump.
13. Pump installation according to one of claims 6 through 12, characterized in that the ejector pump (2) is arranged in or on the well (3), in particular at the end of the suction line (10).

The aim of the invention is to improve delivery of the multi-phase especially hydrocarbons from a well and to limit the free gas volume. According to the invention, a partial liquid flow (13) is branched off on the pressure side from the main supply flow and is delivered on the high-pressure side to at least one jet pump (2) that is disposed on the suction side (1) as an auxiliary delivery device. The pump installation comprises a feed line (7) linking the pressure chamber of the displacement pump (1) with the high pressure side of at least one jet pump (2), said jet pump (2) being disposed on the suction side in the direction of delivery of the displacement pump (1).

METHOD FOR DELIVERING MULTI-PHASE MIXTURES AND PUMP INSTALLATION

Documents:

Inventors:

PCT Conventions: