Institut Francais Du Pe'trole

Roland Lenormand

Patrick Egermann

Marc Fleury

Christophe Chaput

Daniel Longeron

Gabriel Ringot

Arnaud Templier

Francoise Deflandre

Moricio Hoyos

Fabrice Bauget

Pierre Forbes

Joêlle Behot

Annick Eisenzimmer

Method of determining the permeability of an underground medium from NMR logs of the permeability of rock fragments from the medium, based on prior calibration of the permeability resulting from this measurements, from direct measurement on rock fragments, such as cuttings for example. The method mainly comprises measuring permeability (k) from rock fragments, measuring the signal produced by a device allowing NMR analysis of the rock fragments previously saturated with a protonated liquid (brine for example), obtaining optimum values for the parameters of a relation giving the permeability as a function of the NMR signal, and applying this relation to the well zones that have already been subjected to NMR logging but for which no direct permeability measurements are available. One example of one of the applications for the present invention is the evaluation of a hydrocarbon reservoir.

Method of determining the permeability of an underground medium from NMR measurements of the permeability of rock fragments from the medium

A method for forming a model simulating production, by an underground reservoir subject to depletion, of hydrocarbons comprising notably relatively high-viscosity oils. From laboratory measurements of the respective volumes of oil and gas produced by rock samples from the reservoir subject to depletion, and the relative permeabilities (Kr) of rock samples to hydrocarbons, a model of the formation and flow of the gas fraction is used to determine a volume transfer coefficient (hv) by means of an empirical function representing the distribution of nuclei that can be activated at a pressure P (function N(P)) which is calibrated with reference to the previous measurements. Considering that the nuclei distribution N(P) in the reservoir rocks is the same as the distribution measured in the laboratory, the numerical transfer coefficient corresponding thereto in the reservoir at selected depletion rates is determined using the gas fraction formation and flow model, which allows predicting the relative permeabilities in the reservoir and the production thereof which is useful for reservoir engineering.

Method for modelling the production of hydrocarbons by a subsurface deposit which are subject to depletion

A method with application for evaluation or production of a reservoir for determining multiphase flow parameters of a porous medium such as a rock, from the interpretation of displacement experiments. From an injection experiment on a rock sample, the saturation profiles are measured in different sections of the sample. The experimental data are then subjected to a preliminary interpretation by means of a numerical simulation code allowing production of simulated pressure profiles. These profiles are then combined with the measured saturation profiles so as to evaluate the local properties of the sample in terms of capillary pressure. These properties are then re-injected into the simulator as input data so as to finely interpret the flow parameters while respecting the evolutions of the differential pressure, of the displaced fluid production and of the saturation profiles.

Method of determining multiphase flow parameters of a porous medium taking account of the local heterogeneity

Method and device for determining the formation factor of underground zones from drill cuttings. The device comprises a cell () associated with a device for measuring the electrical conductivity of the cell with the content thereof. The cell containing the drill cuttings is filled with a first electrolyte solution (A) of known conductivity (&#x3c3;). After saturation of the drill cuttings by first solution (A), the global electrical conductivity (&#x3c3;*) of the cell with the content thereof is determined. After discharging first solution (A), the cell containing the drill cuttings is filled with a second electrolyte solution (B) of known conductivity (&#x3c3;), and the global electrical conductivity (&#x3c3;*) of the cell containing the second solution and the cuttings saturated with the first solution is determined. The cuttings formation factor (FF) is deduced therefrom by combination of the measurements.

Method for determining of the formation factor for a subterranean deposit from measurements on drilling waste removed therefrom

A method and device evaluate simultaneously, with the same equipment, physical parameters such as the absolute permeability and the porosity of fragments taken from a fragmented natural or artificial porous medium. The porosity of the fragments is measured by means of helium pressure tests according to a protocol known in the art. The chamber () containing the fragments is communicated with a tank () whose volume is also known and containing helium at a known pressure. At pressure balance, the value of the solid volume can be deduced. The rock envelope volume and the fragments mass are also measured. Combining these measurements allows to determine the porosity of the samples and the density of the rock. Their permeability is then measured by immersing them in a viscous fluid and by communicating the chamber with viscous fluid at a determined pressure contained in a vessel () so as to compress the gas trapped in the pores of the rock, according to two different protocols. The values of the physical parameters are determined by modelling the evolution of the pressure or of the volume in the chamber and by means of an iterative adjustment.

Method and device for evaluating physical parameters of an underground deposit from rock cuttings sampled therein

A method of evaluating the capillary pressure curve of rocks of an underground reservoir from measurements on rock debris or fragments such as cuttings from the reservoir, over the total saturation range of these rocks, within a short period and at a low cost, from these measurements is disclosed. The method comprises measuring the permeability k of the debris, measuring the capillary pressure curve Pc as a function of the saturation of these fragments initially saturated with a fluid (brine for example) by subjecting them to centrifugation, and parametrizing a capillary pressure curve Pc satisfying empirical relations depending on adjustable parameters, constrained to adjust to an asymptotic part of the capillary curve measured by centrifugation, and to the value of permeability k measured on the cuttings, so as to obtain the whole of the capillary pressure curve. Applications include hydrocarbon reservoir evaluation.

Method of evaluating the capillary pressure curve of an underground deposit rocks based on rock cuttings measurements

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 () in which they are contained is communicated with a tank () 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 () 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.

Method and device for evaluating physical parameters of an underground reservoir from rock cuttings taken therefrom

Capacitive probe measuring the level, in a vessel and with high precision, of the interface between a conducting fluid (F) and a non-conducting fluid (a gas or oil for example), suited to work under high pressure and high temperature conditions. The probe comprises a preferably tubular insulating layer () made of a dielectric heat-resisting material (a metal oxide such as zirconia or alumina) baked at a high temperature, with a first face in contact with conducting fluid (Fl) and an opposite face in contact with a second electrode (), consisting for example of a coating or of a layer made of a fusible alloy deposited on the opposite face of insulant (), selected according to the temperature range within which the capacitive probe is intended to work, or possibly of an added tube. Alloys based on zinc, tin, copper, etc, can for example be used. A second capacitor of the same type used for temperature compensation of the first one can be placed within the tubular insulating layer. Its capacitance is for example of the order of 1 nF. The probe can be applied in laboratory apparatuses working under high pressure and high temperature conditions, notably in petrophysical test cells.

Capacitive probe for measuring the level of an electricity-conducting liquid in a vessel and method of manufacturing such a probe

Capacitive probe measuring the level, in a vessel and with high precision, of the interface between a conducting fluid (F ) and a non-conducting fluid (a gas or oil for example), suited to work under high pressure and high temperature conditions. The probe comprises a preferably tubular insulating layer ( ) made of a dielectric heat-resisting material (a metal oxide such as zirconia or alumina) baked at a high temperature, with a first face in contact with conducting fluid (F ) and an opposite face in contact with a second electrode, consisting for example of a coating or of a layer made of a fusible alloy deposited on the opposite face of insulant ( ), selected according to the temperature range within which the capacitive probe is intended to work, or possibly of an added tube. Alloys based on zinc, tin, copper, etc, can for example be used. A second capacitor of the same type used for temperature compensation of the first one can be placed within the tubular insulating layer. Its capacitance is for example of the order of 1 nF. The probe can be applied in laboratory apparatuses working under high pressure and high temperature conditions, notably in petrophysical test cells.

Capacitive probe for measuring the level of an electricity-conducting liquid in a vessel

Method of evaluating physical parameters of an underground reservoir from rock cuttings taken therefrom

A process involves placing a solid sample imbibed or saturated with a first fluid (for example water) in a closed chamber; injecting, via pressure means, another liquid under pressure at a first end of the chamber to drain or expel the first liquid from the sample; and sweeping an opposite end of the chamber with a low pressure liquid, circulated by pumping means, which carries or discharges the drained first liquid outside the chamber. A device for conducting the process includes measuring means for determining the pressure and saturation variations of the sample at at least one point of the length of the sample in the chamber, the amount of fluid discharged from the chamber, and the electrical resistivity of the sample. A progressive variation of the flow of the liquid injected allows complete draining and imbibition cycles to be performed while setting up capillary pressure variation curves and calculating relative permeabilities, without touching the sample. Applications for the process include testing of geological samples, as well as building materials used in the building industry.

Process and device for measuring physical parameters of porous fluid wet

The process mainly consists in placing a sample previously imbibed with a first fluid into a vessel or bucket containing another fluid of different density and in applying a centrifugal force by rotating the bucket at the end of an arm, so as to study the displacements of the fluids in the sample during at least two distinct phases. During the first phase, the rotational speed is increased so as to drain the first fluid from the sample. During the second phase, the rotational speed is progressively decreased. In order to avoid a discontinuity and to allow an imbibition of the sample, it is important to keep the two fluids in permanent contact with the sample. The amount of fluid produced in the bucket by centrifugation may be determined. The fluid produced may also be transferred into a variable chamber, for example inside the same bucket or a second rotating bucket.

Process and device for surveying the properties of a permeable material

In a process and apparatus for measuring the distribution of the concentrations of constituents of a centrifuged medium containing at least one fluid, during centrifuging, a mechanical signal, preferably a sound wave, is emitted from at least one emission point (19-22) in contact with or in the immediate vicinity of the medium (16). The emitted signal is received by at least one reception point (20-22) in contact with or in the immediate vicinity of the medium. For each emission-reception point pair, at least one propagation characteristic of the signal between the emission and reception points thereof is measured and, by an appropriate processor (15), the distribution of the concentrations of the constituents present in the medium is determined. A proposed application is the calculation of the relative permeability and capillary pressure curves of fluids in a porous medium in order to improve the working and operation of oil fields.

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Rueil Malmaison, France

Roland Lenormand