COMBINED CHARACTERIZATION AND INVERSION OF RESERVOIR PARAMETERS FROM NUCLEAR, NMR AND RESISTIVITY MEASUREMENTS

摘要

A method of determining the distribution of shales, sands and water in a reservoir including laminated shaly sands using vertical and horizontal conductivities derived from nuclear, NMR, and multi-component induction data such as from a Transverse Induction Logging Tool (TILT). From the resistivities of the sand laminate, empirical realtions are used to predict anisotropic reservoir properties of the reservoir. The TILT data are inverte d based on anisotropic assumptions about laminated shale, with bulk permeabili ty as a measurement (103) constraint; and an assumption that sand comprises a number of intrinsically isotropic layers which gives a model such as a Thoma s- Stieber and Waxman-Smits model, that comrises laminated sands including wate r and dispersed clay, laminated shales and clay-bound water is isotropic. Estimates of inverted shale volume are compared to the estimate from nuclear logs. A difference between the two estimates is an indication that the sands may be anisotropic. A check is made to see if a bulk water volume determined from the inversion is greater than a bulk irreducible water volume from NMR measurements. NMR data are then used ot obtain sand distribution in the reservoir.