The efficiency increasing of acid treatments on the Vereyskiy object of the Gremikhinskoe field

Nadezhda S. Buldakova JSC Izhevsk Oil Research Center Izhevsk, Russian Federation NSBuldakova@udmurtneft.ru
Olga A. Ovechkina JSC Izhevsk Oil Research Center Izhevsk, Russian Federation OAOvechkina@udmurtneft.ru
Nadezhda V. Novikova JSC Izhevsk Oil Research Center Izhevsk, Russian Federation NVNovikova@udmurtneft.ru
Elena Y. Korobejnikova JSC Izhevsk Oil Research Center Izhevsk, Russian Federation EYKorobejnikova@udmurtneft.ru
Elvira Z. Korotkova JSC Izhevsk Oil Research Center Izhevsk, Russian Federation EZKorotkova@udmurtneft.ru
The reserves deterioration of hydrocarbons on the Udmurtiya fields, which is characterized by abnormal geological conditions, high-viscosity and paraffin-base oil, caused the low efficiency of traditional methods of bottom-hole formation zone treatment. The using of hydrochloric acid treatments usually causes a number of well problems that leads to the production rate decrease. We suggest using improved acidic compositions, containing multifunctional reagents-modifiers in the article. The acid compositions were tested for compatibility with reservoir flows; the abilities of new compounds for the formation of emulsions, sediments, and the stabilization of iron (III) were determined; the estimation of the corrosion spreadingrate in the compositions was carried out. The optimal proportions of additives in the inhibited hydrochloric acid for the Vereyskiy object of the Gremikhinskoe oilfield are defined.
Materials and methods
The imitation of interaction processes of acidic compounds for bottom-hole treatment on the Vereyskiy object of the Gremikhinskoe oilfield.
Results
The researches of acid compositions, consisting of inhibited hydrochloric acid with the addition of modifying additives, were carried out, the possibility of increasing the efficiency of hydrochloric acid bottom-hole formation zone treatment, using these reagents, was shown.
onclusions
1.The laboratory researches showed, that the inhibited hydrochloric acid, used in Udmurtneft', is able to stabilize iron ions(III) at the concentration of 4000 ppm at a temperature of 20 and 28 under the conditions of the Gremikhinskoe oilfield. However, the interaction of the acid working solution with the produced oil at the ratio of acid:oil = 1:1, 1:3, 3:1, leads to the formation of secondary emulsion, the influence of which on thewell operation after the hydrochloric acid bottom-hole formation zone treatment can be negative.
2. The positive effect after the adding of modifiers can be achieved only with acertain additives content. In relation to the Vereyskiy object of the Gremikhinskoe oilfield the compositions 3-7 canbe recommended (tab. 2).
3. These acid compositions do not cause the formation of heavy oil sediments and, consequently, they reduce the possibility of secondary emulsions formation. In addition, the corrosion rate of steel in the compositions is lower than in the working solution of inhibited hydrochloric acid. These acid compositions, containing not only the inhibited hydrochloric acid, using in Udmurtneft', but also the stimulating agent of oil recovery X-1or X-2 and stabilizer X-3, ensure high efficiency of the bottom-hole formation zone treatment even under the abnormal geological conditions and during the production of high-viscosity and paraffin-base oil.
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bottom-hole formation zone treatment acid treatment the stimulating agent of oil recovery