Development of low-permeability reservoirs (less than 1 mD) is carried out with intensive flooding. Injection is performed at pressure above the formation fracturing pressure that is why in almost every well a spontaneous growth of (injection) induced fractures takes place.The main problem of pressure transient analysis in a low permeability reservoir with spontaneous fracturing is a long linear regime flow observed in the log-log plot and the absence of a basis to achieve a pseudo-radial flow. To increase the accuracy of well testing in spontaneously fractured injection wells, certain field tests were developed and run. While testing, an injection well with spontaneously induced fractures was shut-in before the bottom-hole pressure went below the fracture closing pressure, then injection resumed for a short period of time, and then the well was shut-in again to record the pressure fall-off curve. The second pressure fall-off curve shows that the pseudo-radial flow developed, because the close of the part of the fracture without proppant occurred.The paper shows field examples of interference well tests exhibiting fracture growth up to 1700 m diagnosed in injection wells. Examples of successful restriction of injection well operation and application of correlation relationships of fracture closing pressure vs. formation pressure to lower water-cut in production wells with water breakthroughs are described.

This article is devoted to examine the pressure behavior during well tests at the system with two finite-conductivity vertical hydraulic fractures. An approximate numerical solution of the problem is obtained, simu-lation of studies by interference test is conducted. This was done by correlating the amplitude of the pressure in the observation well at the distance between two fractures with the fracture flow conductivity. The established mathematical model is used to interpret field case which have been get by method of interference test on a deposit with the low permeable reservoir.

In the paper we study pressure behavior in a system with two wells with finite-conductivity hydraulic fractures in a low permeability formation. We present numerical solution of the problem, sensitivity analysis for the system parameters, our model using by modeling interference test. The numerical model is used to interpret field measured data and to determine the system parameters.