Using numerousexperimentalandfield researches, it was established that there are rock deformations duringoil and gas fields development, occurred due to thereservoir response. It has been established that formationvolume of pore space is decreased due to elastic expansion of rock grains and increase of compression strength transferred to matrix from mass of overlying rocks due to formation pressure depletion. As the result, there are deformation processes in porous medium accompanied by degradation of its porosity and permeability, and suffered greater change compared to the formation porosity, sufferedpermeability at the samepressure variation. Demonstration of mentioned anomalies under formation conditions leading to non-linear effect can strongly influence the whole process of the reservoir development and lead to various qualitative and quantitative differences between the observed facts and the indicators which were calculated using standard methods. Formulas for determination of debits of incomplete horizontally branched wells (HBW) in deformed formation for various number of horizontal shafts in a battery were obtained in this work using image method of drains (sources) and superposition. Obtainedestimate indicatorscan be used inengineering works during development of the deposits indeformed environment.
Formation conditions and exploration prospects of Sinian large gas fields, Sichuan Basin
