bluuebunny/crossref_metadata_2025_split huggingface dataset:
DISTRIBUSI DAN POLA SESAR DAERAH KEPALA BURUNG (PAPUA BARAT)
Authors: Muflihah Imarotul 
Published: November 2015

<p>Pergerakan tiga lempeng di Indonesia, yakni lempeng Asia, lempeng Indo-Australia dan lempeng Pasifik menimbulkan unsur-unsur tektonik yaitu gempa bumi. Hampir seluruh wilayah Indonesia mengalami aktifitas tektonik, salah satu wilayah yang mengalami tektonik aktif adalah daerah Kepala Burung, Papua Barat. Daerah ini diduga terdapat pertemuan tiga lempeng tersebut. Penelitian geologi dan evolusi daerah Kepala Burung dimulai beberapa tahun lalu oleh beberapa peneliti. Studi tentang pergerakan lempeng yang mempengaruhi Kepala Burung menjelaskan bahwa lempeng benua Indo-Australia pada saat ini bergerak relatif ke utara sedangkan lempeng samudera Pasifik bergerak ke barat-daya. Deformasi akibat tumbukan oblique kedua lempeng ini terekam pada sejarah tektonik Kepala Burung dan seluruh daratan New Guinea. Akibatnya pada daerah Kepala Burung ini sering terjadi aktifitas tektonik hampir setiap hari pada setiap tahunnya. Dari penjelasan geologi tersebut diduga terdapat sesar-sesar aktif yang mana perlu dikaji lebih lanjut mengenai sesar-sesar di daerah Kepala Burung tersebut.</p> <p>Tahapan penelitian ini dilakukan tiga tahap. Pertama, Data gempabumi yang yang digunakan adalah data sekunder yang diperoleh dari database gempa internasional yang dikelola oleh <em>United States Geological Services(USGS), </em>dan dari global CMT yang berpusat di Amerika Serikat. Kedua, Dari data global CMT tercatat data-data berupa <em>beach ball</em>, strike, dip, slip/rake-nya sehingga dapat dilihat mekanisme sesar. Ketiga, Pemetaan persebaran gempabumi dengan menggunakan Arcview GIS 3.3. Setelah dilakukan tahap-tahap tersebut kemudian dilakukan analisis data.</p> Berdasarkan analisa data yang telah didapatkan dari hasil penelitian yang dilakukan, disimpulkan bahwa gempabumi yang terjadi di daerah Kepala Burung (Papua Barat) sebanyak 410 gempa, dan terdapat empat jenis sesar/patahan yaitu sesar geser, sesar naik, sesar turun dan sesar oblique. Jumlah sesar dari kejadian gempabumi tersebut adalah sebagai berikut : Sesar geser sebanyak 113 kali, sesar naik sebanyak 142 kali , sesar turun sebanyak 89 kali, sesar oblique sebanyak 73 kali. Dari jumlah sesar tersebut yang paling dominan di wilayah penelitian terjadi sesar naik.
Immigration enhances fast growth of a newly established source population
Authors: Santoro Simone , Green Andy J. , Figuerola Jordi 
Published: November 2015

AbstractImmigration and local recruitment play a central role in determining the growth rate of breeding populations. Unraveling these processes in newly established populations is of great importance to increase our understanding of how species change their distributions in response to global change. We studied the largest colony of glossy ibis (Plegadis falcinellus) in Western Europe (established in 1996 in Doñana, SW‐Spain) by using capture‐recapture methods, count estimates, and projection matrix modeling to: (1) test the effect of resource availability and competition on local recruitment dynamics, (2) investigate the contribution of local recruitment vs. immigration on population growth, and (3) assess the role of this population in source/sink dynamics. We found different dynamics before and after the establishment of satellite colonies in Doñana in 2004. Between 1996 and 2003, the population increased rapidly, fueled by immigrants (≈58 breeding females/yr). Between 2003 and 2007, however, both colony size increase and immigration were negligible. Immigration played a major role in colony growth, but simultaneously this colony was a source population driving expansion of the species range as suggested by (1) absolute and relative estimates of the observed growth rate relative to that predicted by self‐recruitment, and (2) numerous observations of Doñana‐born individuals breeding elsewhere. Local recruitment, which was particularly high for first‐year individuals (probability >0.8 for the early study years), was not directly related to resource availability or previous‐year breeding success. Local recruitment decreased rapidly at a threshold population size, however, when other satellite colonies became established at Doñana. Our study suggests that even when recruitment at an early age and high productivity are observed, immigration can still play a pivotal role in promoting the fast growth of new populations at the edge of a species range, at least until density‐dependent effects arise. This process can be so fast that within a few years a new population can itself become a source population, further driving range expansion of the species.
Experiment Investigation of Steam Flooding of Horizontal Wells for Thin and Heterogeneous Heavy Oil Reservoira
Authors: Huang Shijun , Huang Chenghui , Cheng Linsong , Liu Tian , Chen Zhiming , Mao Wenhui 
Published: November 2015

Abstract
Steam flooding of horizontal wells has long been considered as one of the most effective methods to unlock thin heavy oil reservoirs. Large volumes of heavy oil are located in heterogeneous porous medium containing high permeability wormholes or low permeability shale barriers. Strong heterogeneity can be the main result of early steam channeling. There is a question of how the heterogeneities enhance or hinder the steam chamber advancement, the flow of high viscous oil, steam and condensed water under a steam flooding process in a thin heavy oil reservoir. The shape of the steam chamber is a key element of calculating steam sweep efficiency, confirming the recoverable reserves, determining the moment of steam channeling, optimizing the well spacing, etc. In this paper, we present a series of physical experiments investigating the steam flooding using horizontal wells for thin and heterogeneous heavy oil reservoir. The apparatus mainly consists of simulated formation containing dual parallel horizontal wells. The shape of the steam chamber is obtained by using the Kriging interpolation method. The steam chamber sweep efficiency, oil recovery and water cut of homogeneous model and heterogeneous models are compared. The results indicate that the low permeability zones greatly hinder the development of steam chamber, resulting in poorer sweep efficiency, earlier steam breakthrough, more residual oil, as well as lower oil recovery, higher water cut, less liquids and oil production. The pressure behavior of the horizontal wells are also investigated.
Hydrocarbon Recovery Maximization in Reservoirs Located Close to Potential Water Producer Horizons: New Proposed Methodology to Combine Water Control and Fracture Stimulation Processes
Authors: Sierra Leopoldo , Eoff Larry 
Published: November 2015

Abstract
Hydrocarbon production and recovery maximization can be a challenging task in some specific areas or reservoirs. Specifically, in low permeability environments, hydraulic fracturing is a necessary step to improve the wells productivity and it can be easily justified or applied in reservoirs where a nearby water bearing zone is not present or the water bearing zone is far away from the productive horizons.
When bottom water or water bearing zones are located near the oil producer layers, hydraulic fracture stimulation is normally aborted or the potential layer is abandoned or not completed; unfortunately, the luxury of stimulation or completion abortion is not really the best decision because a large amount of hydrocarbons is located in such complex environments.
For the situations where the fracture stimulation could not be avoided, the industry has used different alternatives to minimize water production. These include selective perforation and controlled fracture stimulation, selective water control treatment into the water producer layer followed by fracturing, or combining the water control and fracture stimulation in one. For the latter methodology, the water control chemical is squeezed first into the fractured interval or the chemical is added into the fracturing fluid pad to minimize water mobility. However, this methodology relies on the compatibility of the fracturing fluid and the water control chemicals or the migration of the water control chemical from the fracturing fluid system to the water source layers to be effective.
This paper proposes a new methodology to minimize water intrusion in cases where fracture stimulation is necessary in areas with bottom water or water bearing zones near the oil producer layers by performing on-the-fly coating of proppant with a relative permeability modifier (RPM) chemical. In the new proposed methodology, water mobility in the water producer layer will be controlled by the proppant bed coated by the RPM.
Successful Execution of an Exploratory Drilling Program Within Extremely Sensitive Environments in Ecuador
Authors: Benalcazar F. L. , Valdivieso S. 
Published: November 2015

Abstract
In Ecuador, back in 2006-2007, the Operator of Blocks 14 and 17 concluded a large exploration project with the construction of Batata 2 well pad and the drilling of two exploratory wells pursuing the confirmation and development of oil reserves identified during the seismic work started in 2003 by EnCanEcuador (Subsidiary of EnCana), in the north area of Block 14. All this development occurred within the Yasuni National Park, one of the natural areas with the highest biodiversity in South America and also traditional land of peoples living in voluntary isolation (Tagaeri and Taromenani).
The Company developed and implemented implementation a sound environmental and social project management that included a sensitive stakeholders engagement and involving plan, the implementation of a permanate HSE team on site focused on audit operations on a daily basis, a community monitoring program, an strong constractor selection process, and a set of best construction and drilling parctoces.
This paper summarizes some of the most important elements of project planning and execution of Batata 2 well pad. Now, years after its execution, we can do a retrospective analysis to identify some of those practices, to highlight them and to present them to our colleagues in the industry. Now the Life Cycle Management is a well know environmental management tool, and the Batata 2 project is a suceesful study case of a properly managed project that represents the commitment from the oil industry to develop and execute projects under the highest social and environmental standards.
A Comprehensive Workflow for Reservoir Characterization and History Matching Applicable to Cretaceous Naturally Fractured Reservoirs in Mexico
Authors: Mehranfar R. , Larez C. J. , Paredes J. E. , Villasana J. C. 
Published: November 2015

Abstract
Most of the Cretaceous fractured reservoirs in Mexico are producing from reservoirs with very poor matrix quality and therefore matrix, for the most part, cannot support the fluid flow into fracture and further on towards the wellbore. Considering other important factors like reservoir rock wettability, which is supposed to be oil wet for this type of rock, small matrix block height, and possible capillary continuity between blocks, the effective production mechanism from these reservoirs (fluid transfer from matrix to fracture) changes from capillary imbibition dominated to gravity drainage and viscos dominated.
Based on the interpretation of field production data as well as discrete fracture network modeling results, most of the movable oil is considered to be stored in the fractured system, and little participation from matrix to the produced fluid is expected. Also considering the very heterogeneous nature of these reservoirs caused by extended systems of faults and fractured, it is very common that this kind of reservoirs can be divided into different compartments with completely different dynamic behavior.
In this work, we try to present a dynamic workflow to compartmentalize the reservoir into isolated or partially isolated blocks, which is the first step in reservoir history-matching process. Later, and through considering the reservoir effective production mechanisms that are discussed in the bulk of the study, a layered history matching process will be presented. In developing this workflow, the raw and interpreted data as well as the final reservoir history-matched models of several fields located in the area have been taken into account to be able to calibrate the workflow and propose a comprehensive procedure that can be of use in similar cases.
Fracturing-to-Production Simulation Approach for Completion Optimization in the Vaca Muerta Shale
Authors: Suarez M. , Pichon S. , Lacentre P. , Badessich M. Fernandez 
Published: November 2015

Abstract
Production modeling is a process that requires analyzing several steps, from reservoir characterization, completion and hydraulic fracturing, up to the optimization in the production system. Traditionally these processes can be analyzed independently with separated specialized tools. However in unconventional reservoirs, as the Vaca Muerta shale, dependency between the stimulation treatment and the well productivity is critical. This work proposes a workflow to evaluate the joint impact of hydraulic fractures with the static and dynamic characterization of the reservoir.
The available static information (geophysics, petrophysics, geomechanics and natural fracture interpretation) is integrated to build a geological model. Then, hydraulic fracturing is simulated numerically using the Unconventional Fracture Model (UFM). The model takes into account the interaction between the existing natural fractures and the created hydraulic fractures during the stimulation treatment. The resulting geometry of the hydraulic fractures is gridded in an unstructured manner. The model reproduces explicitly the volume and permeability with the appropriate distribution along each branch of hydraulic fractures according to the executed completion. Dynamic simulation can be run to perform a history match of the available production data. Hydraulic fracture geometry, driven by geomechanics and natural fractures, is a key component of the process and might be reviewed if no production match can be achieved making the overall workflow iterative. Additionally, automation through assisted history matching is proposed to investigate different possible solution and reduce the timeframe of the study.
Once calibrated with production, the model allows several applications. The different possible solutions considered by the assisted history match process permit the evaluation of the uncertainty of final recovery when forecasting production. Sensitivity analysis over a given hydraulic fracture geometry shows the major role of the matrix saturation and conductivity degradation over the final recovery. Completion can be optimized by considering different scenarios and showing the direct correlation between generated propped surface and well productivity. Different fracture designs can be investigated to increase the propped surface highlighting the importance, not only of the proppant volume, but also of the proppant transport capability of the fracturing fluids to be used.
Geomodeling Workflow Adapted to a Mature Extra Heavy Oilfield. Case Study: Modelization of Petrocedeño Deltaic Reservoir for the EOR Polymer Project
Authors: Mulder R. , Tinedo C. 
Published: November 2015

Abstract
The following paper describes the geomodeling workflow developed for the deltaic reservoirs setting of the Petrocedeño onshore extra-heavy oil field. A modelling strategy was defined to meet the requirements of history matching and polymer injection simulation by first identifying, then implementing in the model, the key geological features which influence production and polymer injection. Furthermore, the methology defined allows the model to respect a vast amount of well data, and to be easily updatable. As a case study, a sector model was constructed in the area selected for the polymer injection pilot project.
In the first step the geological concept is incorporated using deterministic paleogeographic maps, defined using well data and net-sand maps to delineate the main channel belts and floodplain depositional environments. Within this framework, facies associations are modeled using a stochastic algorithm (SIS), with as an additional input a probability cube guiding their vertical and lateral distributions. The probability cube combines the vertical proportion from well data with probability maps derived from shale thickness maps between reservoir units. Facies are consequently modeled (SIS) within the facies associations, followed by classical petrophysical modeling (SGS) per facies.
This workflow's novelty is in the two step modeling of facies associations within the depositional environments prior to facies and petrophysical modeling. The first step gives a strong deterministic input, adapted to a mature field constrained with over 1000 wells. The second step, stochastic modeling within a deterministic framework, has several advantages.
A key aspect is the easy incorporation of all well data, including horizontal wells, as well as the ability to quickly update the model with automatic workflow. With 70 new wells being drilled each year this is a significant advantage. Furthermore, the use of a custom made probability cube permits an accurate representation of the vertical trends within each interval as well as the distribution of barriers between reservoir units. Finally, stochastic approach allows better control of the distribution of the channels internal heterogeneities, a key factor for flow simulation in a polymer injection project.
Oil Recovery in Low Permeability Sandstone Reservoirs Using Surfactant-Polymer Flooding
Authors: Marliere C. , Wartenberg N. , Fleury M. , Tabary R. , Dalmazzone C. , Delamaide E. 
Published: November 2015

Abstract
Surfactant-Polymer flooding is usually not applied in low permeability reservoirs mainly due to injectivity problems in the presence of mobility control agents. Indeed, in the case of surfactant-polymer injection in low permeability formation, one of the major problem is to avoid the plugging of the core due to the jamming of polymer molecules in small pores. Hence, a compromise between molecular weight, concentration and viscosity must be determined. Here we demonstrate the feasibility of a surfactant-polymer EOR process in a sandstone reservoir core with a permeability around 1 mD.
Coreflood experiments were carried out on a sandstone reservoir core using a formulation consisting of a low molecular weight HPAM polymer and a typical oil recovery surfactant, that improved i) the mobility control as well as ii) the interfacial tension decrease between oil and the aqueous phase. The studied system consisted in a 1 to 3mD permeability and 15% porosity sandstone reservoir core, with dodecane as model oil and a 64g/L NaCl brine at 60°C. Specific petrophysical protocols were used to avoid non-uniform saturation profiles at irreducible water saturation (Swi) generated by strong capillary effects that are typical of low permeability media. In addition to the usual mass and volume measurements, we also used the X-Ray CTscan imaging in order to obtain saturation profiles at various steps of the EOR process.
The injection of a low molecular weight polymer solution was possible without plugging the core by choosing the polymer concentration so as to increase the mobility ratio but remaining under the critical entanglement concentration. A first slug of surfactant-polymer solution was injected followed by a polymer postflush. Due to the high amount of clays in the low permeability rocks we used a salinity gradient in postflush to minimize the important adsorption of the surfactant during the injection of the formulation and increase the oil recovery of the process. Saturation measurements were done after each experimental step (100% brine, Swi, ROS and Sor) and revealed a good correlation between the different methods. Thanks to this strategy it was possible to decrease the residual oil saturation (Sor) by at least a factor 2, increasing oil recovery in the range of 40–60% ROIP, compared to standard waterflooding.
The novelty of this work is to use the combination of surfactant and polymer in very low permeability sandstone rocks.
Tena Sandstone: A New Productive Reservoir in the Oriente Basin
Authors: Ruiz R. , Bustos J. 
Published: November 2015

Abstract
The Tena Sandstone, a small horizon belonging to the Tena formation, is presented regionally in the Oriente basin, but has high variability in its productive characteristics, to the point that oil reserves have been recovered from this horizon only in the Blanca-1 well. The information available from the Putumayo, Oriente, and Marañon basins in the upper Cretaceous to Paleogene periods was revised, and a summary table of correlation was performed. Based on the information from the Blanca-1well, and other nearby wells, the stratigraphic features of the Tena Sandstone have been defined. Using 3D seismic data and petrophysical information obtained from wells drilled in the area, the structural and the static models have been elaborated. Considering the production history and the behavior of fluid pressure, material balance was applied in order to estimate the original oil in place. A dynamic model was initialized and a history matching process was performed. Finally production forecasts were made considering three scenarios: a single production well, the drilling of another production well, and the implementation of a small waterflooding project.
The Blanca field is located in the lower part of the main fault Tipishca-Huaico-Blanca. Structurally it is presented as a series of nodes with a stratigraphic component and a soft structural component. The Blanca-1 well has a ten years production history, with an oil production that goes from 600 to190 oil barrels per day. The original oil in place of the Tena Sandstone, estimated by reservoir simulation, is 14.2 million barrels, and primary recovery with one well reaches 1.9 million barrels. With the drilling of an additional production well and the implementation of waterflooding, the recovery would reach 3.7 million barrels. It is considered that this reservoir may be present and be productive in other wells in this area of the Amazon basin.
The information obtained from the Blanca-1 well, and simulation models performed for the Tena Sandstone at the Blanca field, allows to recommend oil operators to investigate the characteristics of small sandy horizons presented in wells that have been already drilled and in other wells to be drilled in the future in the Oriente basin. This will provide a productive alternative in areas where traditional reservoirs have lost their initial production levels.