Nowadays, the fields of hard recoverable hydrocarbon reserves are involved more often into reservoir engineering process. The problem of recovery is often connected with non-Newtonian rheology of oil and complicated reservoir structure. Now the problem of viscous-plastic fluid flows in isotropic reservoirs is studied enough. But, as a rule the real reservoirs show anisotropy of reservoir properties. That's why taking into account anisotropy at the developments of viscous-plastic fluid flows offer both practical and scientific interest.

The present paper represents the laboratory method of combined determination of absolute permeability and limiting pressure gradient for anisotropic reservoirs. The method for determination a structure of absolute permeability tensor and tensor of limiting pressure gradient on the core samples is based on combined usage of two methods. The first of them is the measurements of ultrasonic waves' propagation velocities through the core sample in the various directions. And the second is the measurements of elastic static deformations of the core sample in the various directions. The usage of specified methods allows to establish the fact of anisotropy at first and further to determine the anisotropy type. Then the necessary number of core samples is sawed out from the drill core in the requisite directions in compliance with the anisotropy type for carrying out hydrodynamics researches.

The results of the determination of absolute permeability tensor and tensor of limiting pressure gradient for anisotropic reservoirs are represented. The results confirm tensor nature of limiting pressure gradient and allow to get law of viscous- plastic fluid flows in anisotropic porous media. Within the frame of suggested method it's possible to determine tensors of phase permeability and construct non-linear fluid flows laws.

Taking into account the anisotropy of reservoir properties permits to describe fluid flow distribution more adequate which in turn makes it possible to optimize direction of horizontal well drilling, to rationalize field development system (well spacing) and finally to increase oil recovery.

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