Pressure transient analysis for reservoirs with low mobility coefficient

Background. Low-permeability reservoirs and reservoirs containing high-viscosity oil are increasingly becoming objects of development due to the deterioration of the reserve structure and a number of negative factors. As a result, the time for the logarithmic derivative of pressure to reach radial flow conditions significantly increases, making it impossible to interpret the pressure buildup curve within an acceptable research time. Objective. To develop and summarize recommendations for the pressure transient analysis in reservoirs with low mobility coefficients. Materials and methods. To solve the set task, known and author-developed methods of interpretation and hydrodynamic research were used. Results. It is shown that the most optimal methods are the following: the drawdown curve instead of pressure buildup curve, the usage of flow models preceding radial flow when interpreting pressure curves for wells with complex geometry and the already traditional interpretation of long-term pressure data using pressure downhole gauges. Conclusions. The proposed methods allow for a reduction in the scheduled shutdown time of well during well test and consequently reduce losses in oil production when solving the problem of determining the filtration parameters of the reservoir and the near-wellbore zone.