Clarifying the geological structure of a gas reservoir using well testing

Background. When designing the field development and clarifying the geological and hydrodynamic model, information about the conductivity of identified faults using seismic studies is needed to assess the interaction between wells located in different blocks. Considering the complex structure of the reservoir (with numerous faults), the long distance between wells and the variability of solutions in response to signals reflected from multiple boundaries, solving this problem by using well testing methods is significantly more difficult. Objective. To develop approaches that significantly reduce the uncertainty in assessing the configuration and conductivity of faults in the well influence zone. Materials and methods. The information obtained from long-term monitoring of flow rate and bottomhole pressure in two wells was used. The presence and conductivity of faults was assessed using well testing methods and specialized software for their interpretation. Criteria for quality were introduced, according to compliance/noncompliance with which a decision was made on the correctness of using a particular model. Results. Using two wells as an example, the application of factor analysis to exclude the least probable models of fault configuration and conductivity is shown. The method of excluding inappropriate or less reliable interpretation models solved the problem of confirming the presence of faults, their number, distance from the wells to them, and their conductivity. Conclusions. The presented approach demonstrates the possibility of significantly expanding the scope of application of analytical models for solving complex geological and hydrodynamic problems.