EXPERIENCE OF USING ACID TREATMENTS IN THE OIL FIELD SUWAYDIYA (SYRIA)

Link for citation: Mohammad Almohammad Alnayef, Zain Alabidin Dalfi Abd Ali Khalaf, Gnidan E.V. Experience of using acid treatments in the oil field Suwaydiya (Syria). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 50-58. In Rus. Relevance of the research is caused by the need to increase oil recovery from wells developed in the fields of Syria, in the carbonate reservoirs of the Massif and Shiranish formation, for which there is a natural drop in production rates due to decrease in reservoir pressure, water cut, opening of reservoirs with low reservoir properties and increase in the share of hard-to-recover reserves. The main aim of the study is to analyze the results of acid treatments to improve oil recovery in the field of Suwaydia, Syria. The object of study is the carbonate complexes in the Upper Cretaceous deposits of the Massif formation and the Shiranish formation, Syria. Methods: review of domestic and foreign experience in treating the bottomhole formation zone using acid compositions and analysis of production, technological, lithological, geological, geophysical, and field data of wells treated with acids. Results. The paper introduces the advantages of the acid treatments method, such as improving the reservoir permeability and decreasing the skin factor by increasing the pore space and fracture channels, as well as removing the filter cake and various inorganic sediments that prevent oil flow. The undesirable effects of acid treatments: corrosion, secondary sedimentation, water cut, are indicated. The geological and physical conditions of the well and reservoir for choosing a treatment technology are considered. They are: reservoir temperature, filtration, and reservoir properties of rocks, granulometric (fractional) and mineralogical composition of rocks, chemical composition of reservoir fluids. The main directions of measures for solving geological and technological complications that arise during acid treatments using inhibitors, new multicomponent compositions of acid agents, special additives, and multi-stage treatments are noted. The paper introduces the technology and results of the application of acid treatments: hydrochloric acid treatment and foam hydrochloric acid treatment of the bottomhole zone of wells located in the north-east of the Syrian Arab Republic, which belong to the two oil field – Suwaydia and Zarba – of the Al-Hasakah Oil Fields Administration. It was noted that the use of a simple hydrochloric acid treatment of several wells did not lead to the predicted increase in oil recovery, and the use of an acid mixture (HCL at a concentration of 15 %, HF at a concentration of 3 %) in well no. 462 of the Suwaydia oil field showed an increase in productivity of 1,5 times. Recommendations are given for improving acid treatments at the Suwaydia, Syria fields to intensify oil production.