RO130366A2 - Hydraulic drive group for crude oil pumping unit - Google Patents

Abstract

The invention relates to a hydraulic group for the drive of a hydraulic cylinder of a pumping unit used for oil production. According to the invention, the group consists of a framework () on which a reservoir () accommodating the hydraulic fluid and a system for heating the same are mounted, on a cap of the reservoir () there being a temperature sensor (), a pilot circuit () with accumulators, a hydraulic unit () and some control and pressure control apparatuses (), respectively, a motor () being mounted on the framework (), a flange () being mounted integral with the flange thereof and integral with a set of pumps (), i.e. a constant-delivery and a variable-delivery one, respectively, where the variable-delivery pump () is provided with a proportional pilot circuit (), the pumps () being driven by the shaft of the electric motor (), using a resilient couple, by a common shaft, on the framework () there being also an electric switchboard (), a hydraulic unit () provided with an accumulator () for storing the recovered energy, provided with a control apparatus () and some valves (), the connecting circuits being designed so as to permit operation according to the cyclogram, for driving a hydraulic cylinder () of a pumping unit, a flow-rate transducer () mounted on a pumped oil collecting pipe, some stroke end sensors () and a displacement transducer (), which are suitably mounted on the hydraulic cylinder () to permit the working beam pace to be regulated, by means of a proportional pilot circuit (), a cooling unit () and a filtering system () ensuring the hydraulic fluid normal parameters.

Description

HYDRAULIC GROUP FOR PUMP UNIT AND PIPE

The invention relates to a hydraulic unit for the oil pumping unit, used for actuating the hydraulic cylinder of the pumping unit.

Hydraulic groups for the oil pumping unit are known, which include a variable flow pressure pump, driven by the shaft of an electric motor by means of a coupling, provided with actuation schemes for one or more hydraulic cylinders, with or without recovery system. energy.

The disadvantages of these constructions are due to the high energy consumption and the low reliability, due to the equipment with a single hydraulic pump.

The technical problem solved by the hydraulic unit for the oil pumping unit, according to the invention, consists in optimizing the energy consumption by summing the flow rates discharged by a fixed and variable flow pump, the work cycle automation, the energy recovery at the empty stroke. and adjusting the pump unit's tact according to the deposit.

The hydraulic unit for the oil pumping unit, according to the invention, solves the above problem by having a variable flow pressure pump, and a constant flow pressure pump, which are mounted on a common shaft driven by a electric motor by means of an elastic coupling. In the initial state the connection valves to the consumer are closed for the fixed flow pump to charge the pilot circuit. For the traction actuation of the hydraulic cylinder of the pumping unit the two valves are opened and the pump with fixed flow and the pump with adjustable flow, with proportional adjustment, cumulates the required flow depending on the speed imposed by the technology. After confirming the traction stroke, the descending stroke of the consumer is performed, under the action of the pumping rods, with energy recovery by charging the high pressure accumulator. When confirming the descent stroke, the hydraulic accumulator releases the accumulated energy in the traction circuit and when reaching the pressure regulated in the system the fixed flow pump and the adjustable flow pump ensure the flow required to continue the traction stroke. The cycle is repeated. A flow transducer mounted on the crude oil pipeline allows the evaluation of the flow rate returned to the traction stroke of the pumping unit and the proportional regulation of the flow pump

Ο 1 3 - Ο Ο 8 5 2 - 1 5 Ί1- 2013

variable. The hydraulic scheme includes a system for monitoring the temperature, heating and cooling of the hydraulic fluid as well as a system of filtration of the hydraulic system, with monitoring of the clogging and purity of the hydraulic fluid.

The hydraulic unit for the oil pumping unit, according to the invention, has the advantage that it can be used in difficult working conditions, at extreme temperatures, with high energy efficiency, even in the case of deposits with limited resources.

The following is an example of an embodiment of the invention, in connection with:

- Figure 1, which represents a three-dimensional view of the hydraulic group;

- Figure 2, which represents the hydraulic diagram;

- figure 3, which represents the operating cycle.

The hydraulic unit for the oil pumping unit, according to the invention, consists of a frame A on which the reservoir B is fixed, which incorporates the hydraulic fluid, its heating system, not shown, on the tank cover being mounted the temperature sensor 1, the circuit of piloting 2 with accumulator, hydraulic block 3 with control equipment 4 and pressure control 5, from frame A being mounted electric motor 6, integrally with its flange by fixing flange 7, integral with the pump set, with constant flow 8, and with variable flow 9, the variable flow pump being provided with the proportional control circuit 10, pumps driven by the axis of the electric motor through an elastic coupling, not shown, through a common axis, of the frame A being mounted the electric panel C, the hydraulic block 11, provided with a battery 12 for storing the recovered energy, provided with control equipment 13 and valves 14 and 15, the connection circuits being made conf rm of the hydraulic diagram to allow the operation according to the cyclogram, for the actuation of the hydraulic cylinder 16 of the pumping unit, the flow transducer 17 mounted on the collection pipe of the pumped crude oil, the end-of-stroke sensors a, b and the displacement transducer c properly mounted on the cylinder hydraulics 16 allow adjusting the pump unit's speed through the proportional control circuit 10, a cooling unit 18 and a filtration system 19 provide the normal parameters of the hydraulic fluid.

Claims (1)

Hydraulic unit for the oil pumping unit, for actuating the hydraulic cylinder of the pumping unit, characterized in that it consists of a frame A on which the tank B is fixed, which incorporates the hydraulic fluid, its heating system, not shown, on the tank cover. the temperature sensor 1, the pilot circuit 2 with the accumulator, the hydraulic block 3 with the control equipment 4 and the pressure control 5 being mounted, the A-frame being fitted with the electric motor 6, integrally with its flange and the flange 7 is fixed, integral with the set of pumps, with constant flow 8, and with variable flow 9, the pump with variable flow being provided with the proportional pilot circuit 10, pumps driven by the axis of the electric motor through an elastic coupling, not shown, by a common axis, of the frame A being mounted the electrical panel C, the hydraulic block 11, provided with a battery 12 for storing the recovered energy, provided with control equipment 13 and valves 14 and 15, the connecting circuits being made according to the hydraulic diagram to allow operation according to the cyclogram, for actuating the hydraulic cylinder 16 of the pumping unit, the flow transducer 17 mounted on the collecting pipe of the pumped crude oil, the end sensors of the stroke , b and the displacement transducer c properly mounted on the hydraulic cylinder 16 allow the speed of the pump unit to be regulated through the proportional control circuit 10, a cooling unit 18 and a filter system 19 provide the normal parameters of the hydraulic fluid.