COMPLEX APPROACH TO ESTIMATING THE EFFICIENCY OF THE DESIGNED HYDROCHLORIC ACID TREATMENT USING THE RESULTS OF LABORATORY STUDIES AND HYDRODYNAMIC SIMULATION

Abstract

The relevance of scientific work is caused by the fact that at present a high proportion of hydrochloric acid treatments do not provide the expected result in the oil fields of the Perm krai. This problem is directly related to the current approach to the design of technological operations to stimulate oil flow and insufficient knowledge of most of the factors that significantly affect the efficiency of treatment of the bottomhole zone with acid compositions. The demand for improving technologies for acid stimulation of the bottomhole zone of carbonate reservoirs and methods for predicting its effectiveness is caused by the low cost of this operation and the possibility of achieving high well productivity indicators with high-quality design and operation. The main aim of the research is to develop an integrated approach for predicting the technological effect of the projected hydrochloric acid treatment based on a combination of laboratory research results and hydrodynamic modeling. Objects of the research are technologies for enhancing oil recovery of reservoirs, lithologically represented by carbonate varieties. Within the main oil and gas provinces of Russia, most of the fields are at the final stage of development, as a result of which there is a low productivity of wells. Therefore, the improvement of methods for enhancing oil recovery is an important and relevant area of research in the oil and gas industry. Methods: laboratory studies, consisting in determining the carbonate content of the studied sediments, as well as the properties of acid compositions used when carrying out hydrochloric acid treatments at the deposits of the Perm krai. These studies are necessary to establish the numerical value of the change in the skin factor on the objects under consideration. Hydrodynamic modeling taking into account this skin factor to determine the technological efficiency of the projected technology for treating the bottomhole zone of the productive formation. Results. Based on the results of this study, there is a high correspondence between the actual changes in the skin factor at 18 objects after acid treatment, obtained from the analysis of the databases of hydrodynamic studies of wells in the Perm krai, and the predicted values ​​according to the described method of preliminary assessment of the technological effect of hydrochloric acid treatment. The paper introduces the comparative analysis of the actual values ​​of the target well flow rate, recorded during five months of operation, and predicted ones using hydrodynamic modeling of the fully described acid stimulation design, based on the calculated value of the skin factor change. Based on the analysis results, it was found that the proposed comprehensive approach to predicting the effectiveness of hydrochloric acid treatment has a small error within 5 %. Using a hydrodynamic model, the technological effect of the projected acid treatment at the target object until 2030 was calculated and a conclusion was made about the success of this geological and technical measure. With the introduction of the proposed integrated approach to oil companies, it is possible to increase the effectiveness of measures to increase oil recovery.

Keywords

• hydrochloric acid treatment
• complex approach
• hydrodynamic simulator
• skin factor
• effectiveness of measures