An Industry Consortium (BP, ChevronTexaco and Ondeo Nalco Energy Services) conducted a multi-company research project known as Bright Water. The goal of this project was to develop a time-delayed, highly expandable material that would improve the sweep efficiency of a water flood. In November 2001, the first of these water flood profile modification treatments was pumped in the Minas field. The Minas Field, located on the island of Sumatra in Indonesia, has an OOIP of 8.7 billion barrels, is at nearly 50% recovery, and has water-cuts greater than 97%. Reservoir thief zones have been identified throughout the main reservoir layers. The main objective for pumping a profile modification material is usually to divert injected water out of thief zones and into zones with higher oil saturation, though areal sweep improvement can also be expected. The profile modification treatment of 42,000 barrels water containing 4500 ppm of active material was pumped into Minas injector 7E-12 ("A1" sand). The objective of the field trial was to verify that significant volumes of this low cost material could be pumped deep into the reservoir at low viscosity, and then expand after a pre-designed time interval. Injection tracer studies were conducted pre- and post-treatment to aid in determining changes to the injection sweep efficiency. A bottom hole pressure fall off test was also used to measure post - job permeability. The trial demonstrated that large volumes of the material can be pumped into the formation without raising the injection pressure or blocking the injection well bore, can propagate in the rock pore system, and then will expand at a pre-designed time. Changes in oil production after the trial will be discussed along with the field data acquired during and after the trial. As part of the continued development of this material, a second trial commenced in late November 2002 on a North Sea (UK) production platform. The treatment was successfully placed in mid December, 2002. Introduction This paper presents a case history in which a novel profile modification treatment was pumped in the Minas waterflood. Of all the problems that can beset oil wells, unwanted water production is one of the most troublesome, yet water flooding to improve the recovery of oil is the most common secondary recovery process used in the modern oil industry. Water production causes many problems such as corrosion, scaling, cost of oil water treatment and cost of disposal. In water injection projects excess water production is often linked to poor sweep efficiency, which renders significant amounts of oil irrecoverable during the economic life of a field. Poor sweep efficiency can be the result of zones with unfavorable permeability in heterogeneous reservoirs or unfavorable mobility ratio within homogeneous rock. Specifically water can break through from the water injection to the oil production wells in the most permeable zones while significant oil is left in the reservoir (Fig. 1) or it can pass through low mobility oil by a process of viscous fingering.1 The problem can be even more severe when bottom water zones with high water saturation and therefore variations in relative permeability exist. 2,3

Diversions of water from irrigated agriculture are occurring in the western United States to address increasing municipal and industrial demands. Deficit irrigation of alfalfa (Medicago sativa L.) could be a source of water without complete dry‐up of irrigated fields. Water saving potential from alfalfa is high because it is a high water‐use crop produced on 12% of the irrigated land in the United States. The objectives of this paper are to review alfalfa plant–water relations in the Great Plains and Intermountain West, to understand potential water savings through deficit irrigation, and to indentify management practices that maximize water‐use efficiency (WUE). Alfalfa biomass yield exhibits a linear relationship to evapotranspiration (ET) with the slope of a regionally aggregated water production function of 0.16 Mg ha−1 cm−1 Relative ET declines 30% faster than relative biomass yield under deficit irrigation or dryland management. Because early season harvests have greater WUE, combining full irrigation in spring with no irrigation during less efficient water‐use growth periods may be more effective in saving water than season‐long deficit irrigation. Management practices that can influence WUE under deficit irrigation include stand age, growth stage at harvest, and alfalfa variety. A potential complication with controlled deficit irrigation of alfalfa is an uncertain contribution to ET from a water table. As alfalfa roots develop over time, a significant percentage of total ET can come from water tables shallower than 200 cm and the percentage increases as availability of water from precipitation or irrigation declines.

ABSTRACT. Building models is an important way of integrating knowledge. Testing and updating models of social-ecological systems can inform management decisions and, ultimately, improve resilience. We report on the outcomes of a six-year, multidisciplinary model development process in the sagebrush steppe, USA. We focused on creating state-and-transition models (STMs), conceptual models of ecosystem change that represent nonlinear dynamics and are being adopted worldwide as tools for managing ecosystems. STM development occurred in four steps with four distinct sets of models: (1) local knowledge elicitation using semistructured interviews; (2) ecological data collection using an observational study; (3) model integration using participatory workshops; and (4) model simplification upon review of the literature by a multidisciplinary team. We found that different knowledge types are ultimately complementary. Many of the benefits of the STM-building process flowed from the knowledge integration steps, including improved communication, identification of uncertainties, and production of more broadly credible STMs that can be applied in diverse situations. The STM development process also generated hypotheses about sagebrush steppe dynamics that could be tested by future adaptive management and research. We conclude that multidisciplinary development of STMs has great potential for producing credible, useful tools for managing resilience of social-ecological systems. Based on this experience, we outline a streamlined, participatory STM development process that integrates multiple types of knowledge and incorporates adaptive management.

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Federally funded university water programs have had limited success in halting the degradation of water resources in agricultural, rural, and urbanizing watersheds for the past five decades. USDA-funded university water programs have advanced our understanding of watershed processes and the development of best management practices (BMPs; e.g., conservation tillage, nutrient management, alternative and innovative septic systems, and riparian buffers) to mitigate environmental risks from anthropogenic activities, in particular from agriculture, to our water resources; yet water degradation persists and has worsened in many watersheds (Howarth et al. 2000;Mueller and Spahr 2006). The National Research Council (2012) stresses the need for sustainable agricultural practices to reduce changes in flow regimes and water quality.In this research editorial, we make four points relative to solving water resource issues: (1) they are complex problems and difficult to solve; (2) some progress has been made on solving these issues; (3) external nonstationary drivers such as land use changes, climate change and variability, and shifts in markets, policies, and regulations warrant constant vigilance to assure that presumed improvements are being attained; and (4) we are poised to make substantial progress on these challenges over the next 10 to 20 years if critical steps are taken. Our discussion is framed by identifying and describing four grand challenges that we face in agricultural, rural, and urbanizing watersheds: nutrient management, food safety, agricultural water use, and groundwater management. These four grand challenge areas were distilled from a listing of over 50 important issues related to agricultural water resource management identified at a workshop of university and government water scientists in November of 2011. Our over-