Assessment of the Reliability of Reserves Estimates of Public Companies in the U.S. and Canada.

Estimation of reserves is a process used to quantify the volumes of hydrocarbon fluids that can be recovered economically from a reservoir, field, area or region, from a given date forward. A considerable level of uncertainty is involved throughout the reserves-estimation process. Unfortunately, individuals are poor at assessing uncertainty, with a common tendency for overconfidence (underestimation of uncertainty) and optimism. There are a few studies that address the reliability of reserves estimates, but none of them quantify the reliability of these estimates. This research aims to assess quantitatively the reliability of reserves estimates of public companies filing in the U.S. and Canada. To do this I measured biases in reported reserves estimates for 34 companies filing in Canada and 32 companies filing in the U.S. over the time period 2007 to 2017. Canadian companies explicitly report technical revisions of proved (1P) and proved-plus-probable (2P) reserves. U.S. companies do not report “technical revisions,” but instead report “revisions of previous estimates” and revisions due to price changes of proved (1P) reserves separately. I calculated Revisions Other Than Price (ROTP) by subtraction for U.S. companies and assumed the difference was the same as “technical revisions.” Based on probabilistic reserves definitions, it is reasonable to assume that proved reserves estimates are expected to have positive technical revisions 90% of the time, while proved- plus-probable reserves estimates are expected to have positive revisions 50% of the time. The reliability of proved and proved-plus-probable reserves estimates was assessed using calibration plots, in which the frequency of positive technical revisions is plotted against the estimate probability. Calibration plots can be used to measure confidence bias, ranging from underconfidence to complete overconfidence, and directional bias, ranging from complete pessimism to complete optimism. “Technical revisions” reported by 34 Canadian companies for the 11-year period were positive an average of 72% for 1P reserves and an average of 54% for 2P reserves, whereas the expected values were 90% and 50%, respectively. Thus, on average over this time period, filers in Canada overestimated 1P reserves and underestimated 2P reserves. Considering the entire reserves distributions, bias measurements indicate that filers in Canada were moderately overconfident and slightly pessimistic. Revisions Other Than Price (ROTP) calculated for 32 U.S. companies for the 11-year period were positive an average of only 51% for 1P reserves, compared to an expected 90%. Thus, on average over this time period, filers in the U.S. overestimated 1P reserves significantly. Considering the entire reserves distributions, bias measurements indicate that filers in the U.S. were somewhere between complete overconfidence and neutral directional bias, and moderate overconfidence and complete optimism. The biases in reserves estimates filed in both Canada and the U.S. suggest that adjustments in reserves estimation procedures are warranted. Three groups of professionals can benefit from this study: (1) estimators, who can use the methodology to track their technical revisions over time, calibrate them, and use this information to adjust future estimation procedures; (2) investors, who can analyze reported reserves estimates to compare volumes fairly; and (3) regulators, who can ensure that filers are complying with appropriate criteria for 1P and 2P reserves

Processes of MISS-formation in a modern siliciclastic tidal flat, Patagonia (Argentina)

The study focus on the description of several MISS as erosional pockets and remnants, flipped-over edges, and large microbial deformation structures as roll-ups, folds and gas domes, in the context of sediment composition, hydraulics, and geomorphology. The aim of the paper is to recognize the mechanisms of formation of MISS by analyses on hydrodynamics under the influence of the geomorphology. The study was conducted in an elongated inactive tidal channel colonized by microbial mats (2.5 × 0.3 km) in a progradation environment. To continuously record the water-level fluctuations, a HOBO water level logger was placed 40 cm below the flat surface for two years. The sea water enters several times a year, during storms, where the flood currents were characterized by faster velocity than ebb currents, reaching a water depth up to 0.70 m over the tidal flat. That coastal process creates MISS over the tidal flat. The most conspicuous microbial structures are the huge deformation roll-ups several m-scale, associated to elongated rip-off mats, folds and flipped over mats. The process of fluidization was postulated to explain the sand-infilling of gas domes and folds we observed. This process would result from the wave action on the water column that produces a temporal fluid behavior of the underlying sand.Fil: Maisano, Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Cuadrado, Diana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Gomez, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Tecnológica Nacional. Facultad Regional Bahía Blanca; Argentin

Sediment transport inferred by submarine bedforms

By means of bathymetric and side scan sonar records, the net circulation of sediments caused by tidal currents and waves in the outer Principal Channel of Bahía Blanca Estuary is inferred. On the northern coast of the studied area there are two harbours, Belgrano and Rosales, which are simultaneously affected by internal and external hydrosedimentological processes. Through this study, present and potential negative interactions between human activities and natural processes within the studied area are demonstrated.A través del análisis de registros batimétricos y de sonar de barrido lateral se infiere la circulación neta de sedimentos causada por olas y mareas en el sector externo del Canal Principal del estuario de Bahía Blanca. Sobre la costa norte del área de estudio se encuentran dos puertos, Puerto Belgrano y Puerto Rosales, los cuales son simultáneamente afectados por procesos hidrosedimentológicos internos y externos al estuario. Por medio de este estudio se evidencian las interacciones negativas, presentes y futuras, entre las actividades humanas y los procesos naturales.Fil: Cuadrado, Diana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Gomez, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Ginsberg, Silvia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

Integrating literature across the first grade curriculum through thematic units

Transformational theoretical model -- Literature-based thematic units -- Reading, writing, listening, and speaking

The sustainable supply chain's contributions to the development to Colombia and it's enterprises.

Este artículo muestra los beneficios tanto internos como externos de implementar una cadena de abastecimiento sostenible. Explorando todos los eslabones de la cadena y analizando las estrategias que conllevan al crecimiento de las compañías. Así mismo expone las diferentes certificaciones y sellos ambientales que existen, demostrando su importancia y validez para el mercado. Por otra parte hace alusión a cuatro casos sostenibles indicando una parte del informe de sostenibilidad de cada compañía y adicionalmente se exponen los principales indicadores ambientales que se deben contemplar.The following article identifies the internal and external benefits of the implementation of sustainable supply chains. This article explores the activities of the supply chain and analyzes the strategies that assist in entrepreneurial development. The ensuing discussion explores environmental certifications and their role in the market. This article details cases of four enterprises that utilize the sustainable supply chain and their sustainable annual report, also shows the environmental indicators to look at

ANALYSIS OF THE EFFECTS OF ENVIRONMENTAL REGULATION ON PULP AND PAPER INDUSTRY STRUCTURE

Environmental regulations are hypothesized to have an impact on industry structure in manufacturing industries. A nonstationary Markov chain analysis shows that the capital expenditures required to meet environmental regulations is a statistically significant variable explaining increasing concentration of production capacity in the pulp and paper industry.Environmental Economics and Policy, Research Methods/ Statistical Methods,

Developing Animal Feed Preservatives From Paper Mill Byproducts

Our objectives were to evaluate the antifungal properties of technical lignins against 3 molds and 1 yeast causing hay spoilage, and for their ability to preserve alfalfa hay nutritive value. In experiment 1, 8 technical lignins and propionic acid (PRP; positive control) were tested at a dose of 40 mg/mL. The experiment had a randomized complete block design (RCBD, 4 runs) and a factorial arrangement of 3 molds × 10 additives (ADV). The effects of ADV on the yeast were also evaluated with a RCBD. Across fungi, sodium lignosulfonate (NaL) and PRP were the only treatments with a 100 ± 2.8% inhibition. In experiment 2, the minimum inhibitory (MIC) for selected technical lignins and PRP were determined. Among technical lignins, NaL had the lowest MIC across molds (\u3c 33.3 mg/mL) and MgL for the yeast (26.7). However, PRP had values that were several fold lower across all fungi (\u3c 3.33). In experiment 3, a RCBD (5 blocks) with a 3 (ADV; NaL, MgL, and PRP) × 4 (doses: 0, 0.5, 1, and 3% w/w fresh basis) factorial arrangement of treatments was used to evaluate the preservative effects of ADV in high moisture alfalfa hay inoculated with a mixture of the fungi previously tested and incubated under aerobic conditions. After 15 d, relative to untreated hay (14.9 ± 0.77%), DM losses were lessened by doses as low as 1% for NaL (3.39) and 0.5% for PRP (0.81). This was explained by a reduced mold count in both NaL at 3% (3.92 ± 0.55 log cfu/fresh g) and PRP as low as 0.5% (3.94) relative to untreated hay (7.76). Consequently, sugars were best preserved by NaL at 3% (10.1 ± 0.283% DM) and PRP as low as 0.5% (10.5) vs. untreated (7.99), while keeping NDF values lower in NaL (45.9 ± 0.66% DM) and PRP-treated (45.1) hays at the same doses, respectively, relative to untreated (49.7 ± 0.66% DM). Hay DMD was increased by doses as low as 3% for NaL (67.5± 0.77%), 1% MgL (67.0), and 0.5% PRP (68.5) vs. untreated hay (61.8). In the case of NDFD, 0.5% for MgL and PRP (30.5 and 30.1 ± 1.09% DM, respectively) and 1% for NaL (30.7) were the lowest doses increasing NDFD relative to untreated hay (23.3). Total volatile fatty acids were increased to the greatest extent by NaL at 3% (111.9 ± 1.3 mM) relative to spoiled hay (86.7). Across technical lignins, NaL was the best hay preservative. However, its effects were limited compared to PRP at equivalent doses. Despite not having an effect on preservation, MgL improved DMD by stimulating NDFD. Further research needs to be conducted to isolate the most antifungal fraction of NaL and to understand the stimulatory effects of MgL on fiber degradation. Keywords: hay preservation, technical lignins, ruminal digestibility

Campesinos and the State: Building and Experiencing the State in Rural Communities in the 'Post-conflict' Transition in Montes de María, Colombia

This research is an ethnographic study of relationships and interactions between campesino communities and the state during the escalation of the armed conflict and the ongoing 'post-conflict' transition in the mountain zone of Montes de María, Colombia. This study contributes to the understanding of state building 'from below', with a focus on rural areas in contexts of 'post-conflict' transitions. I examine forms of political violence carried out in campesino communities by state actors during the militarization of the region and the long-term effects of that violence on campesinos and their relationships with the state. I analyze how citizen-state relationships and experiences of the state are shaped in the 'post-conflict' transition in rural areas, in the context of state processes centered on the victims of the armed conflict and the implementation of the peace agreements between the Colombian government and FARC guerrillas. I explore continuities of violence in campesino communities during the last decade. I also examine state images constructed in these territories. I argue that state violence carried out in campesino communities as part of counterinsurgency practices constituted rural populations as subjects at the margins of the state. Practices of producing visibility and invisibility of past state violence by campesinos and state actors and the lasting effects of violence continue shaping relationships with the state. The Law of Victims and Land Restitution created opportunities regarding the rights of the victims. However, campesinos experiences have also been shaped by the partial or slow fulfillment of reparations and a politics of waiting. As part of the peace accords, the Development Plans with a Territorial Focus created opportunities to reshape citizen-state relationships by relying on a territorial approach and a participatory process. Rural communities participated actively in the formulation of these plans but the rights of these populations have yet to materialize on the ground. Finally, institutional efforts to reshape relationships between the state and rural inhabitants have coexisted with structural violence and the threats that social leaders continue to face in rural areas. Narratives and images of state abandonment continue being constructed and mobilized by campesinos in a context of state interventions

Assessing the Transformative Significance of Movements & Activism: Lessons from A Postcapitalist Politics

How do researchers and/or practitioners know when change efforts are bringing about significanttransformation? Here we draw on a theory of change put forward by the feminist economicgeographers, Julie Graham and Katherine Gibson. Proposing “a postcapitalist politics” thatbuilds on possibility rather than probability, they direct theoretical attention and communityengaged action research to recognizing and supporting non-capitalist economic practices andsensibilities that already exist despite the dominance of capitalism that keeps them hidden andignored and to understanding the “reluctant subject” of change efforts. We enter into aconversation with their theory of change by inferring criteria for assessing significance and usingthose criteria in dialogue with two social movements we have researched: the feminist movementin Bogotá in the 1970s and 1980s and the contemporary local food movement in North Carolina.Lessons from these movements, in turn, help refine the criteria. Gibson-Graham are unusual – andconsequently resonant with cultural-historical activity theory and related social practice theoriesof identity – in that they bring into dialogue theorists of the political and those interested inembodiment and the micro-politics of everyday life enabling both to better understand and supportconditions for positive social and economic transformation

Morfodinámica de un campo de dunas submarinas en una entrada de marea: San Blas, Argentina

Se estudió la morfología de un campo de dunas submarinas desarrollado en una entrada de marea que conecta la plataforma continental argentina con bahía Anegada (sur de la provincia de Buenos Aires). Se infiere la circulación sedimentaria a partir del desplazamiento diferencial de las geoformas medido en relevamientos consecutivos. Como parte de la metodología se utilizó un ecosonda y un sistema batimétrico por medición de fase (SBMF) denominado GeoSwath que permitieron obtener la morfología submarina en detalle. Se observaron dunas grandes sobre el límite sur del campo de dunas con altura entre 4,5 y 5,0 m y espaciamiento entre 100 y 120 m, a profundidades de 24 m, que se desplazan hacia el exterior del canal a una rapidez entre 18 y 75 m año-1. Hacia el límite norte del campo, a 21 m de profundidad las dunas eran de menor magnitud, entre 2,0 y 2,5 m de altura y espaciamiento entre 40 y 80 m, y se desplazaron a una rapidez entre 18 y 36 m año-1 hacia el interior de bahía Anegada. Se obtuvo la distribución del flujo de agua en toda la columna, en un perfil perpendicular al canal relevado, mediante ADCP. Los valores máximos de rapidez de corriente fueron durante la marea creciente, alcanzando 2,0 m s-1. Los resultados obtenidos permiten definir un modelo circulatorio de transporte de sedimentos arenosos, con la formación de un delta de marea de flujo en la cabecera de la entrada de marea y un delta de reflujo en el límite del dominio oceánico, unidos por una garganta de marea profunda, exenta de sedimentos inconsolidados.The morphology of a submarine dune field developed in a tidal inlet that connects the Argentinean continental shelf with Anegada Bay (southern Buenos Aires province) was studied. The sediment circulation was inferred from the differential displacements of the bedforms evaluated by comparing consecutive surveys. An echosounder and a Phase Measuring Bathymetric System (PMBS) called GeoSwath were used to obtain a detailed submarine morphology. Large dunes, with heights between 4.5 and 5.0 m and from 100 to 120 m separating them, were present near the southern limit of the dune field at 24 m depth. These dunes move towards the outer part of the channel at a speed of 18 to 75 m year-1. At the northern end of the dune field, at 21 m depth, the dunes are smaller, being 2.0 to 2.5 m in height and separated by 40 to 80 m. The smaller dunes move towards the interior of Anegada Bay at 18 to 36 m year-1. The distribution of the water flow in the entire water column was obtained through a perpendicular profile of the channel by means of an ADCP. Maximum current speeds were 2 m s-1, and were found during flood tide. The results obtained indicate a circulatory transport model of sedimentary sands, with the formation of ebb and flood deltas at both ends of the deep inlet throat, which lacks of unconsolidated sediments.Fil: Cuadrado, Diana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Gomez, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Tecnologica Nacional; Argentin