A technique for extrapolating core-measured rock mechanical properties from a cored well to an uncored well is presented. The process uses electrofacies and square wave techniques to develop rock mechanical property logs for the uncored wells.
Data from the North LaBarge Shallow Unit (NLBSU) is used to develop the process. The NLBSU wells require hydraulic fracturing to generate economic production rates. The NLBSU produces from Cretaceous-age Mesaverde sandstone that is composed of thinly bedded sand and shale layers. The reservoir heterogeneity caused by these layers complicates hydraulic fracture growth characteristics. Improvements in hydraulic fracture simulation are needed to accurately predict these growth characteristics. This includes improvements in input data, such as rock mechanical properties, for the simulations.
The described methodology uses electrofacies developed from core and FMI in one well and extrapolates the electrofacies to other wells via an AO10 induction log curve (depth of investigation 10 in (25 cm)). Induction logs are run in almost every well in the field and provide a universal extrapolation medium without incurring additional costs. The process uses acoustic velocity measurements for rock mechanical values, but any accepted measurement technique can be used. Only two major facies are present in the NLBSU and the presented technique only addresses the two facies. However, the methodology can be expanded to include more facies if cutoff values can be established.
The process described in this paper is being used to improve hydraulic fracture modeling in the NLBSU. It can be used in other fields which need improved modeling also. Additionally, it can be used for any computer simulation program that requires rock mechanical property input including reservoir simulation and wellbore stability programs.