To overcome the shortcomings of conventional, near-wellbore profile modification methods, a microbial profile modification (MPM) method with spores was investigated. A halotolerant, spore-forming mesophile was isolated and characterized. These biopolymer-producing spores propagate easily in Berea cores with permeabilities more than about 500 md. With a specifically formulated nutrient package, they are readily germinated and produce biofilm, which reduces the permeability of the rock. The depth of penetration and the degree of permeability reduction can be controlled by varying injection schemes.
No abstract
Soil salinity has emerged as one of the most serious and widespread consequences of the climatic wet period affecting the northern region of the American Midwest since 1993. Groundwater levels have increased, causing not only millions of hectares of prevented planting in the Dakotas, but also much higher levels of soil salinity on otherwise productive soils. A persistent comment from producers throughout eastern North Dakota during the wet cycle was that salinity had emerged in areas where it was never a problem before. Management techniques to reduce salinity effects include crop selection, use of cover crops after harvest, calcium chemical amendments for sodic soils, tillage changes to reduce upland recharge, and tile drainage to lower water tables. Soil data collected to establish background salinity and sodicity levels on a Nahon soil map unit (fine, smectitic, frigid Calcic Natrudolls) east of Wheatland, ND are presented with a broader interpretation regarding the need to perform soil chemical sampling for certain soils before installing tile drainage.
In this paper we present a methodology to verify and update geostatistically based reservoir models using numerical simulation and automatic history matching of well-test data. A Bayesian estimation technique provides the framework for the inversion procedure used to update reservoir models. A restricted-step Gauss-Newton method and an extension of Carter's method for sensitivity coefficients make the methodology efficient and practical. Reservoir models (permeability, porosity and skin factor) can be updated based on individual simulation cells, geological feathers, or on constant multipliers applied in the well-test radius of investigation. When short-term well-test data is available from many wells, we found it useful to calculate property multipliers around each well and then interpolate the multipliers to unsampled areas in the reservoir. Field examples demonstrate the utility of conditioning reservoir models with well-test data. In the examples, flowing bottomhole pressure mismatches are as high as 2000 psi and core based permeabilities deviate by two orders of magnitude from the well-test results. After conditioning to well-test data, pressure mismatches are significantly reduced, permeabilities are updated to the correct magnitude, and the skin factor closely matches the classic well-test analysis result. We applied our updating methodology to a full-field simulation study on a large carbonate reservoir. Comparisons of historical pressure and production data to the updated full-field model demonstrate good agreement.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.