Well processing before repairing
During the mechanized wells operation process, downhole pumping units’ failure occurs very often.
The most common reasons for pumping equipment failure are rocks and produced fluids properties:
• accumulation of mechanical impurities or sand, taken out of the formation as a result of creating a pressure drop or depression in weakly cemented reservoir rocks;
• the formation of paraffin deposits on the pump intake and on the inner surface of the tubing, caused by the concentration of high molecular weight hydrocarbons of the alkane series in the extracted oil, as well as temperature and pressure changes during oil production;
• crystallization of salt deposits on working facilities of downhole pumps with changing temperature and flow velocity, as well as the presence of highly mineralized water in the formation fluid.
In addition, well productivity decrease might often be caused by paraffin and scale deposits formation in its bottom-hole or filter zone, or the formation of persistent emulsions. As a consequence, it leads to pump operation failures or pump rate decrease, and further to unscheduled costly well repairs provided by workover team.
However, all complications mentioned above can be eliminated without involving the workover team.
Technotec International organized well processing brigades, which include specialized vehicles, high-pressure pumping units, as well as qualified personnel in many regions of Russia. Brigades are provided with the necessary stock of chemical reagents, such as dispersants, scale removers and others.
Initial complication detection and immediate response of engineers make it possible to carry out a certain well treatment and recover it, what in turn allows to prolong the overhaul period of the well and not to involve the workover team.
By treatment we mean flushing the working parts of pumps from the mechanical impurities and paraffin deposits using large volumes of an aqueous dispersion-reagent composition, or scale cleaning using scale remover’s solutions.
Such processing becomes even more efficient with the object approach, i.e. by defining specific cleaning period for each well (a period in which the well operates without process parameters complications errors, and by the end of which a routine prophylactic treatment should be carried out).
Well processing completely solves the problem of improving working capacity, and thereby increasing their inter-repair period. For example, at the wells of the Volga and Ural fields, the treatments efficiency was 76% — the normal well operability at these facilities was restored without major repairs.
