The final stage of development of Western Siberia fields has seen degradation of porosity and permeability properties (PPP) of producing formations along with overall well productivity. Various physical, chemical and physical-chemical methods of bottom-hole area (BHA) treatment are applied in order to restore the formation’s PPP.

The most popular methods used at Western Siberia fields, and namely at oil and gas condensate fields of Tyumen Region, include acid treatment, acid and alkaline soaking, and hydraulic fracturing (HF).

HF is one of the most efficient methods of boosting oil and gas production of producing formations. However, due to abnormally low formation pressure, high water content in producing formations and close bottom water occurrence in the wells of Noyabrsk cluster of fields this method has not been widely applied.

Acid treatment is the most harmless method for the bottom-hole area. It involves injection of hydrogen chloride (HCl) or a mixture of hydrogen chloride and hydrogen fluoride, the so-called mud acid (HCl+HF), into the perforations in the well bore. Acid treatment dissolves substances that invade the BHA and cause PPP degradation.

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