With the extensive use of hydraulic fracturing in tight and unconventional reservoirs, there has been a growing need to better geologically characterize the reservoir to maximize hydrocarbon recovery while also reducing the overall cost. Currently, there is a lack of low cost and risk data on lateral wells to improve completion designs and obtain more consistent production from all stages. Most wells are completed based on geometric stage spacing, which does not always provide consistent production from all stages. These sub-economical stages, which contribute little to nothing to final production, reduce the overall profitability of the well.
Traditionally, lateral well completion planning utilizes mainly pilot hole wireline logs, to mitigate the cost and risk of running tools down lateral wells. The resulting interpretation from the pilot hole is then propagated along the intended length of the lateral based on a homogeneous "layer cake" geological model. However, it is a well-known and often overlooked fact that this model does not account for lateral facies or mineralogical changes, that can affect stimulation design and production. A better method for understanding these lateral changes and planning the completion is required, with the optimal case being nominal- to improved-production using strategic staging and cluster selection in an optimized horizontal. The result being reduced cost without reduced production, thereby achieving higher well profitability.
In this paper we review the development of an integrated subsurface completion program combining pilot hole wireline and sidewall rotary core data, with cuttings-based mineralogical data and mudlogs from the lateral. This technique improves lateral well characterization without the risk of wireline runs, by mineralogical analysis of cuttings in real time, calibrated against the pilot hole. The overall objective is to use the enhanced lateral mineralogical data for better completion design and predictive modelling of production.