AUTOMATIC CONTROL METHOD AND DEVICE FOR OIL PRODUCTION PROCESS Russian patent published in 2006 - IPC E21B43/12 E21B47/06 

FIELD: oil and gas industry, particularly to stimulate oil production.

SUBSTANCE: oil production is performed along with controlling of oil production parameters and speed of submersible pump electromotor rotation to maintain optimal values of oil production process parameters. Liquid level in well is chosen as the main oil production process parameter. Volume of liquid to be produced is chosen as parameter to be optimized. Control operation is carried out in several stages in automatic mode. At the first stage initial liquid level in well corresponding to calculated level, which provides maximal liquid inflow into well, is specified in pump motor control unit and pump operational mode is selected so that volume of liquid extracted from well is equal to volume of liquid flowing into well for the predetermined time period. Then liquid level corresponding to above situation is recorded and stored in memory. At the second stage predetermined initial liquid level in well is determined and then influx flow and extracted flow are equalized by pump mode of operation. Obtained value of extracted flow is compared with that at previous stage. If above value exceeds that obtained at previous stage predetermined liquid level is also increased and influx flow and extracted flow are equalized by pump mode of operation to increase predetermined liquid level in well in several stages up to corresponding extracted flow volume reduction. After that one backward step is executed, predetermined extracted liquid level corresponding to above step is taken as optimal level and above level is maintained during well operation. If extracted liquid volume decreases at the second stage predetermined liquid level change direction is performed in reverse order and then all above operations are repeated beginning from the second stage. Device for above method realization comprises electromotor to activate pumping jack, which is connected with submersible pump, extractable liquid volume sensors, well liquid pressure sensors connected to electromotor control unit. The control unit comprises serially connected memory means, frequency regulator and voltage changer. Control device is also provided with acoustic depth finding sensor, which determines liquid level in well and is installed at well head. The acoustic depth finding sensor is connected to one frequency regulator input. Extracted liquid volume sensor is connected to one input of memory means having the second input connected to command operator's console. Well liquid pressure sensor is connected to the second input of frequency regulator having output connected to electromotor through voltage changer.

EFFECT: increased oil output.

1 dwg