Schlumberger Technology Corporation

Khaled Hadj-Sassi

Mohammed Badri

Jean-Marc Donadille

Patrice Ligneul

Stephen Dyer

Mustapha Abbad

A mineralogy composition of a formation of interest is determined using core samples or downhole measurements. A dry permittivity is determined for each identified mineral. A volumetric mixing law is employed using the determined mineralogy composition and the determined dry permitivities. An effective matrix permittivity is determined using results from the volumetric mixing law. Dielectric dispersion measurements of the subject formation are acquired using the core samples or the downhole measurements. A dielectric petrophysical model is produced using the dielectric dispersion measurements and the effective matrix permittivity. A water saturation is estimated based on the dielectric petrophysical model. Nuclear magnetic resonance (NMR) T2 measurements having short echo spacings are acquired. A NMR petrophysical model is generated based on the NMR T2 measurements. A total porosity is determined based on the generated NMR petrophysical model. A total gas-in-place estimate is made using the determined total porosity and the estimated water saturation.

Total gas in place estimate

The wettability of a formation may be estimated using a multi-frequency dielectric measurement tool. Multi-frequency dielectric dispersion measurements are made using the multi-frequency dielectric measurement tool on a sample. The bulk density and the total porosity of the sample are also otherwise acquired. The bulk density, matrix permittivity, total porosity, and multi-frequency dielectric dispersion measurements are input into a petrophysical dielectric model and the petrophysical dielectric model is applied to obtain inversion results. A wettability state of the sample is determined using the inversion results and one or more reservoir management decisions are made based on the determined wettability state of the sample. A non-transitory, computer-readable storage medium may be provided that has stored on it one or more programs that provide instructions. The instructions are executed by a processor and cause the processor to develop an estimation of formation wettability that may be used for reservoir management.

Downhole wettability estimate using multi-frequency dielectric measurements

A system is described for evaluating coagulation of particles in a downhole fluid-particle mixture based on dielectric measurements. An example downhole treatment is one in which flocs are used to plug a high-permeability subterranean formation zone as part of a stimulation procedure. An injection tube is positioned within the wellbore to the high-permeability zone. An instrumented section of tubing includes one or more dielectric probes that are positioned and configured to make dielectric measurements of the particle-fluid mixture flowing in the tubing or in the annulus. The downhole dielectric measurements are used to indicate whether or not the particle-fluid mixture has the desired structural properties. An operator on the surface can make adjustments in real-time according to the received dielectric measurements.

Evaluation of fluid-particle mixtures based on dielectric measurements

Downhole gravity measurements are used to monitor the volumetric sweep of COand estimate the fingering phenomenon if any. The gravity measurements have been found to be effective due to the high density contrast between COand brine or oil which provides better and higher sensitivity. An analytical forward model is used to determine the location and shape characteristics of the flooding front. A strategy to monitor the movement of the COflooding front and to predict the fingering phenomenon is used to provide a warning tool to improve the sweep efficiency, according to some embodiments.

Tracking non-uniform flooding fronts of gas injection in oil reservoirs

A method of simultaneously determining multiple parameters or a parameter distribution characterizing material properties of a volume under investigation using an inversion process of sparse measurements is described including the step of defining an initial model of the volume and modifying the initial model by matching the multiple parameters or parameter distribution with the measurements using alternatingly an iterative inversion method and a probabilistic inversion method, and determining the multiple parameters or parameter distribution after one or more iterations of the alternating inversions.

Method of determining parameter from sparse measurement data

A method of determining the dip or apparent dip of a section of a subterranean formation is described using the measurements of a borehole gravity meter and a dip-dependent model for the response of the gravity meter.

Growing community of inventors

Al-Khobar, Saudi Arabia

Khaled Hadj-Sassi