One hallmark of modern nuclear magnetic resonance spectroscopy is the use of multi-dimensional correlation experiments typically with only spin Hamiltonians. However, spin systems may be affected by interactions and processes that are not controlled through the spin degree of freedom. This paper demonstrates a correlation spectroscopy between two different physical processes, one is NMR spin dynamics, and the other capillary drainage for the study of porous materials. We show that such a correlation experiment produces a joint capillary pressure (Pc) and NMR relaxation (T2) correlation function, Pc-T2 map that probes how pores are connected, an insight not available in conventional NMR or capillary experiments.

Petroleum reservoirs are complex bodies due to geological processes, such as sedimentation, cementation, dissolution, and dolomitization. These processes lead to complex systems of pore bodies and throats. Consequently, reservoir rocks embody tortuous pore structures with a wide range of pore sizes and connectivity. Characterization of the intricate pore networks are especially important in prolific carbonate systems, where diagenesis and secondary porosity can lead to low-resistivity pay or isolated pore systems with high porosity and low permeability. Properly characterizing these body-throat relationships can also help lead to more characteristic permeability calculations.

Two-dimensional spin-spin relaxation (T2-T2) techniques have been developed to probe coupling between different environments such as diffusive coupling between small and large pores or chemical exchange with clays. In these studies, Numerical Laplace Inversion (NLI) is used to obtain two-dimensional T2-T2 relaxation distribution spectrum from the T2-T2 signal decays, and the off-diagonal peaks characterize coupling. Often, these coupling peaks are both weak and close to the diagonal and combined with the inherently ill-conditioned nature of the inversion, their presence is difficult to differentiate from inversion related artifacts and blurring. This manuscript presents a time domain based analysis to identify the presence of coupling that avoids the ambiguities present in T2-T2 spectra. The approach utilizes the symmetric nature of the two-dimensional time domain data, where the presence of curvature along one of these symmetries gives an unambiguous indicator of coupling. Measurements on porous glass beads are used to verify the technique.

L’invention concerne des procedes et systemes apparentes destines a etre utilises dans la fracturation hydraulique et d’autres applications de champ petrolifere. Un corps d’outil est positionne dans un puits de forage a un endroit proche d’une formation rocheuse souterraine fracturee. Le corps d’outil contient une pluralite de fibres continues pouvant etre deployees. Au moins certaines des fibres continues pouvant etre deployees sont deployees dans des fractures a l’interieur d’une formation rocheuse souterraine. Chaque fibre deployee est continue entre le corps d’outil et la formation rocheuse. Le nombre de fibres continues pouvant etre deployees fournit une redondance suffisante pour etablir au moins une mesure cible liee au processus de fracturation.

L'invention concerne des procedes et des systemes associes a utiliser avec un systeme a base de fibres continues dans des operations de completion de puits. Lesdits systemes comprennent une pluralite de fibres continues pouvant etre deployees dans une partie de completion de puits; et un module de gestion de fibres concu et positionne dans le puits afin de faciliter l'etablissement d'une communication avec la pluralite de fibres continues. Le nombre de fibres continues pouvant etre deployees constitue une redondance suffisante pour effectuer au moins une mesure cible concernant la completion.