BRINING WELLS TO STABLE PRODUCTION

Brining wells to stable production is referred to as the process of well development after wire line operations or overhaul, i.e. reduction of back pressure on the formation, creation of depression and inflow stimulation.

During brining the well equipped with the pump unit to stable operation the following parameters are monitored: liquid level in the annulus; annular pressure; buffer pressure; liquid output; solids level; rate of current drawn by the electrical submersible pump; voltage supplied to the electrical submersible pump; insulation resistance.

Process operation of bringing to stable operation is of high priority during operation of submersible pump units special attention which is caused by their design features. Submersible electric motor which is pump drive, needs external cooling which occurs when electrical submersible pump is washed with liquid coming into a well from formation.

aspects:

• Upon the pump start-up, at initial stage of well bringing to stable operation, low inflow (or its total absence) of produced liquid into the well, liquid is pumped out from the annulus between production string and tubing string (annulus), which results in insufficient external cooling of electrical submersible pump located below the pump intake;
• Pumping out of liquid with high density results into increase of load on electrical submersible pump;
• High concentration of salts in the well-killing fluid results into salts deposited on the operating parts of the pump which not only impairs the pump operation but can also cause unit chocking;

The experience gained by the company during the years of operation allows carrying out this type of operation successfully taking into account process difficulties caused by the pump design. Such approach allows preventing pump failure as well as increasing operating efficiency due to selection of the best performance.