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AssigneeInstitut Francais du Petrole
InventorsRoland Lenormand, Patrick Egermann, Arnaud Templier
Estimating the term…
Method and device for evaluating, simultaneously and with a single equipment, physical parameters such as the absolute permeability and the porosity of fragments taken from a fragmented artificial or natural porous medium. The porosity of the fragments is measured by means of pressure tests using helium or any other gas, according to a protocol known in the art. Chamber (1) in which they are contained is communicated with a tank (11) of known volume containing helium at a known pressure. At pressure balance, the value of the solid volume can be deduced. The rock envelope volume and the mass in fragments are also measured. The porosity of the samples and the density of the rock are determined by combining these measurements. Their permeability is then measured by immersing them in a liquid and by communicating the chamber with a liquid initially at a predetermined pressure contained in an accumulator (9) so as to compress the gas trapped in the pores of the rock. The values of the physical parameters are determined by modelling the evolution of the volume of liquid injected in the chamber and by means of an iterative adjustment. Applications: petrophysical measurements from drill cuttings or crushed cores for example.
A method for evaluating, with a single equipment, physical parameters of a fragmented porous medium from rock fragments taken in this medium, comprising a stage of immersing fragments contained in a containment chamber in a liquid and of intermittently communicating the chamber containing the fragments with a source of liquid under pressure comprising an accumulator containing an elastic volume of liquid, so as to compress the gas trapped in the pores of the rock, a stage of measuring the volume of liquid injected, a stage of modelling the evolution of the volume of liquid injected from a priori selected initial values at least for permeability and the residual gas saturation, and a stage of iterative adjustment of the value of the physical parameters of the rock fragments so as to obtain the best possible adjustment of the modelled evolution of the volume injected with the measured evolution of the volume injected in the chamber, characterized in that:
A device for evaluating physical parameters of a fragmented porous medium from fragments taken in this medium, comprising a processing system, a containment chamber for the fragments, an injection assembly for injecting a liquid into the chamber so as to fill the chamber containing the rock fragments, and for carrying out a cycle comprising a stage of liquid injection into the chamber, this assembly comprising an accumulator containing an elastic volume of liquid and means controlled by the processing system for controlling communication of the accumulator with the chamber containing the rock fragments, means for measuring the pressure in the chamber, the processing system being suited for modelling the evolution of the volume of liquid injected from initial values selected for the physical parameters of the rock fragments, and for adjusting iteratively the values to be given to these physical parameters so as to obtain the best possible adjustment between the modelled evolution of the physical quantity and the measured evolution of said quantity in the chamber, characterized in that it comprises pressure measuring means for measuring pressure variations in the accumulator and in that the processing system is suited for calculation of the volume of liquid injected in the chamber from the accumulator, from the pressure variation measured by the pressure measuring means.
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