bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation and Field Test of Combined Gel and Surfactant Imbibition Technology in High Temperature, High Salinity Fault Block Reservoir
Authors: Cai H. , Zhang Q. , Yang S. , Tian M. , Wang Q. , Zhou Z. , Li J. , Zhaoxia Liu 
Published: May 2017

Abstract
Chemical EOR(CEOR) is one of the most effective technologies for the recovery enhancement of mature high water-cut oilfields. Taking Daqing oilfield as an example, great success has been achieved in Alkali-Surfactant-Polymer(ASP) flooding field applications with incremental oil recoveries exceeding 20%. With the depletion of petroleum resources, CEOR methods attract ever-increasing attentions worldwide and expand to reservoirs with harsh conditions, such as high temperature high salinity (HTHS), low permeability, and complicated fault block etc.
CEOR feasibility study was performed for a HTHS complicated fault block with temperature of 78 °C and produced brine salinity at 37570.7 mg/L. Detailed screening and evaluation of CEOR methods including polymer flooding, flowing gel injection, and surfactant imbibition were conducted. Furthermore, core flooding tests were carried out to determine oil displacement performance and optimize injection scheme.
Parallel core flooding test proved that 12.8% incremental oil recovery was obtained by polymer flooding. As to flowing gel injection, a heat tolerant gel formulation was developed with good thermal stability at 78 °C within 30 days. An incremental oil recovery of 14.8% was achieved by flowing gel, 2% higher than that of polymer flooding. Through static imbibition test, an nonionic surfactant with good recovery was selected. Core flooding test resulted in 13.5% incremental recovery by surfactant slug. For combined gel and surfactant imbibition technology, 17.8% incremental oil recovery was achieved in core flooding test.
Pilot test of flowing gel and surfactant imbibition technology was delpoyed in a fault block with 9 injectors and 26 producers. An incremental oil of 2376 MT was achieved after one year injection.
High Resolution Investigations of Flow and Thermal Processes During Production from Hydraulically Fractured Ultra-Low Permeability Media
Authors: Moridis G. J. 
Published: May 2017

Abstract
This study investigates at high resolutions the system behavior caused by water invasion/imbibition during the short period of hydraulic fracturing in ultra-low permeability gas reservoirs, and during the subsequent long-term production period. The main objective is to assess the impact of this early water invasion/imbibition on the flow, fate and recovery of fluids during short- and long-term production from such reservoirs. The study accounts for all known flow and thermophysical processes and uses very fine discretization in order to capture the non-isothermal multi-scale system behavior in sufficient resolution. It focuses on two of the four general types of fractured systems (Types I and II), and describes complex processes and phenomena on length scales that cover the mm- to 15 m range. The high pressure during hydraulic fracturing, coupled with the generally low initial water saturation of such media, cause water imbibition into the matrix, with significant effects on the fluid flow behavior in this region. All key variables (pressure, temperature, phase saturations and relative permeabilities, capillary pressure, etc.) are monitored over time, and the effect on the fluid production rates is analyzed.
The results of the study indicate that penetration of water into the matrix during hydraulic fracturing depends on the type of the fractured system. Flow in the fractures of Type II systems is fast, but water flow and redistribution into the matrix is slow and continues for a long time after the end of hydraulic fracturing, and water evaporation during production may have a significant impact. The phase saturations and relative permeabilities exhibit a complex behavior and vary both spatially and temporally in the matrix (Types I and II) and in the fractures (Type II). Gas production exhibits a complex behavior that is affected by both the evolving relative permeability to gas and the changing pressure and temperature regime. The magnitude of water injection/recovery volumes and the recovery pattern appear to be indicator of the type of reservoir fractured system.
Data-Driven Model Reduction Based on Sparsity-Promoting Methods for Multiphase Flow in Porous Media
Authors: Bao A. , Gildin E. 
Published: May 2017

Abstract
Fast simulation algorithms based on reduced-order modeling have been developed in order to facilitate large-scale and complex computationally intensive reservoir simulation and optimization. Methods like proper orthogonal decomposition (POD) and Dynamic Mode Decomposition (DMD) have been successfully used to efficiently capture and predict the behavior of reservoir fluid flow. Non-intrusive techniques (e.g., DMD), are especially attractive as it is a data-driven approach that do not require code modifications (equation free). In this paper, we will further enhance the application of the DMD, by investigating sparse approximations of the snapshots. This is particularly useful when there is a limited number of sparse measurements as in the case of reservoir simulation.
The approach taken here is the snapshot-based model reduction, whereby one computes a sequence of reservoir simulation solutions (e.g., pressures and water saturations in the case of two-phase flow model) forming a big data matrix – we call this the offline step - that is used to compute basis for representing the states of the system for different input parameters – the online step. The selection of these few basis is the core of the model reduction methods. DMD selects the basis and apply the reduction without knowledge of the inner works of the reservoir simulator, as opposed to the POD methods. Sparse DMD has been introduced recently to determine the subset of the DMD models that has the most profound influence on the quality of the approximation of the snapshot sequence. Two model reduction process are involved. One is offline process, which does not require running the simulator but rather predicting future behavior with linear combination of DMD modes. The other online process incorporates sparsity DMD modes in numerical simulator to release the burden of linear matrix solver.
We first show the methodology applied to a 3-D single phase flow problem. Here we show the DMD modes and its physical interpretations, and then move to two phase flow for 2-D heterogeneous reservoir using the SPE-10 benchmark. Both online and offline process will be used for evaluation. We observe that with a few DMD modes we can capture the behavior of the reservoir models. Sparse DMD leads to the optimal selection of the few DMD modes. We also assess the trade-offs between problem size and computational time for each reservoir model. The novelty of our method is the application of sparse DMD, which is a data-driven technique and the ability to select few optimal basis for the case of reservoir simulation.
Industrial Waste Management of Exploratory Maritime Drilling Activity on the Coast of Bahia State: Case Study of BM-J-2 Block
Authors: Amaro T. P. , Pessoa M. C. , Cardoso-Júnior R. A. , de Campos T. M. 
Published: May 2017

Abstract
The analysis and comparison of solid waste generation, transportation, treatment and final disposal data, generated during two exploratory offshore drilling campaigns (2011 and 2013) in BM-J-2 Block (Jequitinhonha Basin, Brazil) with and without the use of a temporary waste storage exclusive area for this operation aimed to verify the applicability of these two waste management operational alternatives in regions where the oil and gas exploration and production industry is not yet consolidated.
The compliance with Brazilian legal requirements, with the implementation of a Pollution Control Project according to Technical Note CGPEG / DILIC / IBAMA N° 01/11 guideline, allowed the comparision of data generated during the two drilling campaigns, even though they have been generated in different moments. Data generated during the campaigns were critically analyzed and compared using spreadsheets (dynamic tables), elaborated in Microsoft Office (version 2016), considering the need to check the profile of waste generation from both campaigns and to evaluate the effectiveness of two different management strategies implemented.
With the waste generation profile analysis for both campaigns, it was concluded that in the 2013 campaign, procedures that allowed qualitative improvements (such as the increase of the best forms of treatment and disposal and of the range of qualified suppliers for management of waste generated by the company's operations) and/or quantitative improvements (such as the decrease in the number of transportation events and the travelled distances) were adopted.
Despite the need for continuous improvement, based on the results of this study, we can conclude that the Pollution Control Project during the two f offshore drilling activity campaigns in BM-J-2 Block was effective and implemented according to the Technical Note CGPEG / DILIC / IBAMA N° 01 /11 guideline and the use of temporary storage area, although exclusive and built for the operation, is the best management strategy also in areas where the E&P industry is not yet consolidated.
Is important to highlight that for a successful implementation and operation of the storage area, the planning of the whole implementation of the Pollution Control Project needs to be minimally effective, avoiding waste loss and other related issues, fines applied by the environmental licensing agency, disengagement of the operation's workforce and difficulties for licensing future operations.
Golfo San Jorge Basin, Argentina - A Conventional Gas Field Development. Management, Production and Challenges
Authors: Nougués J. M. , Perez-Cometto G. 
Published: May 2017

Abstract
There is a well-known theoretical chart that shows how compression, scales, liquid loading, corrosion, etc. appear as a gas field decreases production due to reservoir depletion. The approach of this paper is ambitious and will demonstrate and exemplify how these problems appeared in our gas field, and share the techniques, methods, and procedures we went through to satisfactorily handle them.
This paper shows the development of a gas field placed in the Golfo San Jorge Basin (Argentina) including the different life stages of the field (High/Medium/Low Pressure) with the related problems in Facilities, Flow Assurance, and Liquid Loading, and finalizes with an introduction to the future problems we are expecting.
Throughout the paper, we will show the changes we went through, lessons learned, and conclusions related to the following topics: + Facilities → Slugging in flowlines/changes in suction pressure/new facilities+ Flow Assurance → Chemical usage for solving organic and inorganic scales. Need of migration from bullheading treatments to CT nitrogen assisted operations. Acid stick treatments.+ Liquid Loading → Foaming agents/Velocity Strings/Capillary Strings/Wellhead Compression+ Tendency of Scales Evolution in produced water.+ Evolution of tubing metallography+ New approaches in PLT interpretation
Not many papers cover in such an integral way the development of a conventional gas field with a large exploitation history as this work does, where the field dates from the 2000s.
This paper sets a reference and fills a gap in terms of an overall look at all problems together, and integrates the theory from the literature, information from field experiences, best practices, and the application of new technologies/methodologies. Challenges for future exploitation are presented as well. Reading this paper will help in understanding the complexity that those people involved in the management of a gas field will face as their reservoirs deplete and the production of the wells goes down.
Finding Incremental Oil In A Field With More Than 50% Recovery And With a Strong Aquifer: How We Did It!
Authors: Boettner M. L. , Thompson A. R. , Barros P. , Berrios V. , Lucero R. A. , Vieytes R. E. 
Published: May 2017

Abstract
The Papagayos formation in the Cuyana Basin, Argentina is one of the most prolific and mature reservoirs in the YPF portfolio. Currently it has a 98% water cut with an estimated recovery factor of 56%. The challenge was to determine if there was untapped oil in the field and subsequently how to economically extract it.
To identify the source of the current oil production and potential new oil, well logs on infill wells were analysed. We also constructed a full field dynamic model that was history matched to production rates, RFT’s, gradient surveys and compared to historical water saturations identified on infill wells.
To reduce uncertainty and to confirm the mechanism by which oil remained in the subsurface, we cross referenced the results of the simulation model against lab 2D visual cells filled with glass spheres to reproduce any trapped oil seen in the simulation.
Well logs saw oil at the top of the reservoir; however it was not known if this oil was mobile. With the parameters history matched, the simulation showed the presence of mobile attic oil underlain by a water saturated zone swept by the aquifer. The simulation also demonstrated that the reservoir has multidarcy permeability; hence water coning would be a major issue to consider.
The simulation model enabled an estimation of the aquifer strength and demonstrated that it would have a major impact on any recovery process. Simulations were made to determine if the aquifer could be either used to assist any new recovery process or otherwise if it could be subdued. Multiple EOR options were considered to exploit this remaining attic oil, however the most economic option was to augment the aquifer by injecting water on the flanks.
Lab results corroborated the simulation and showed that attic oil could be a result of both coning and the structure of the reservoir. Also it was seen that increasing water injection rate into the 2D visual cells (augmenting the aquifer at high water cuts) lead to an increase in oil recovery.
Despite a strong aquifer and both high water cuts and recovery factor, it was possible to identify and develop economic oil by applying an integrated modeling methodology. The model demonstrated that augmenting the aquifer is easier than fighting it by applying an EOR approach that requires massive injection to overpower the aquifer. Linking simulated reservoir response to 2D visual cell displacements demonstrated the effectiveness of flank water injection in increasing oil recovered.
Assessing the Effects of Seismic Survey on Large Mammals, Using Cameras Trap in High Sensitivity Biodiversity Hotspot
Authors: Ferretti V. , Mange G. , Aguerre G. , Juarez M. , Maffei L. , Gomez F. , Capello N. , Mendoza E. 
Published: May 2017

Abstract
This paper presents the results of a research conducted to assess the effects a 2D seismic survey may have had on medium and large mammals living in the Lower Urubamba basin (Cuzco, Peru), performed in the frame of the Camisea Project Biodiversity Monitoring Program (PMB). The research was conducted over an area of 900 ha, characterized by dense amazon rain forest and rich biodiversity, representing one of the 35 world biodiversity hotspots identified by Conservation International.
Thirty four camera traps were installed along the seismic lines. Results yielded significant information regarding the effects diverse anthropogenic disturbances had on medium and large mammals in the course of the survey, concluding that, although some limited impact in time and space were identified, most of the species recorded remained in the surroundings, with little and only temporary drive away. In addition, the survey allowed the identification of 23 mammal species, many of them indicators of good conservation conditions.
Gas Lift Optimization Under Uncertainties in BSW
Authors: De Santana R. S. , Ferreira Filho V. M. , Monteiro D. D. , Chaves G. S. , Duque M. M. , Granja Saavedra A. L. , Baioco J. S. , Teixeira A. F. , Vieira B. F. 
Published: May 2017

Abstract
The production optimization in Oil & Gas fields is an activity which relies on a wide range of parameters and variables, where many of them can vary over time due to production trends and inherent uncertainty. However, while developing the optimal strategy for oil production, it is usual to ignore those uncertainties, which can affect the optimum operational point, leading to disappointment and loss of expected production. This paper aims to analyze the influence of the water cut (BSW) into the gas lift optimization process. Statistical data from producer wells are combined with multiphase flow correlations to estimate the uncertainty in the production variables. A mathematical optimization model is built using the Mixed Integer Linear Programming Technique (MILP), linearizing the oil well performance curves. For each uncertain scenario the optimization model was run. A case study with representative data shows that the uncertainties importance grows in the most constrained scenarios and how the absence of uncertainty can overestimate the expected oil production.
Importance of the Study of Environmental Aspects in the Exploitation of Unconventional Reservoirs for Risk Assessment of the Activity in Argentina
Authors: De La Zerda M. A. , Erdmann E. , Sarandón R. 
Published: May 2017

Abstract
There is an expectation that the exploitation of unconventional hydrocarbons (UH) reservoirs will contribute to satisfy the growing demand of energy, since conventional reservoirs are on a declining stage. However, environmental consequences of the fluids used on unconventional formations are an aspect that has not been analyzed in depth in the region. Approximately 10-40% of the volume injected of fracturing fluids returns to the surface during the hydraulic fracturing process. The flowback not only includes the chemicals added, but may also contain various substances suspended from the formation. This situation demands the development of appropriate technologies for flowback treatment and the need to consider the existing legal context and the ecologic and environmental conditions. The impacts associated with UH activities that need to be analyzed in order to accomplish control and standardization, include those related to consumption of surface water or groundwater, potential contamination of regional water resources, treatment and final disposal of flowback. It is possible to achieve the sustainability of the activity, based on an environmental analysis.
The objective of this work is the analysis of the environmental aspects associated to the extraction of UH (shale and tight). A comparative analysis of the activity, in a national and international context, including legal aspects, technologies used and environmental risk is performed. Additionally, possible mitigation measures of environmental risks are evaluated. The study includes the analysis of the existing environmental legislative framework in different regions where the exploitation of UH could be made. It also includes the analysis of the actual effluent management strategy. A description of the environmental conditions, including climatic, geological, hydrological and ecological conditions is performed in areas with completion activities, in order to identify the regions with higher level of environmental risk. Possible technologies for flowback water treatment and reuse are analyzed, depending on physicochemical characteristics and volumes of water. The novelty of this work is the analysis of the factors that determine the environmental risk in the extraction of UH, especially in the hydraulic fracturing process, which includes technologies, environmental conditions at the site and the legal context in the region. This allows identify the areas of higher and lower level of environmental risk in order to proceed to the identification, implementation and development of potential mitigation measures to achieve the sustainability of the activity.
Uncertainty Analysis for Production Forecast in Oil Wells
Authors: Monteiro D. D. , Ferreira-Filho V. M. , Chaves G. S. , De Santana R. S. , Duque M. M. , Granja-Saavedra A. L. , Baioco J. S. , Vieira B. F. , Teixeira A. F. 
Published: May 2017

Abstract
The oil and gas industry is faced with uncertainty in many activities. Whereas in many of its areas, such as finance, geology and reservoirs these uncertainties are already incorporated in the modelling and studies. This is not the reality when it comes to modelling artificial lift and multiphase flow. Studies related with uncertainties in oil and gas production are limited. Therefore, this paper aims to develop a methodology to identify and quantify uncertainties, obtaining thus more accurate data to be used in production modelling. In addition, the methodology intends to evaluate oil production forecasting considering uncertainty propagation in oil flow simulation software. This study was divided in statistical analysis and production forecasting. An algorithm using R software analyzed and treated production data. It was applied statistical modelling techniques to data series. Deviations from these data were adjusted to a continuous distribution that provides the parameters to be used by Monte Carlo simulation method to generate random values to be input uncertainties of the MARLIM multiphase flow simulator. Oil flow rate, as output simulator, was adjusted to a new distribution and finally the intervals of occurrence probabilities of oil flow rate forecasts. This methodology was applied to BSW (Basic Sediments and Water) data from a representative field, showing the importance of including uncertainty analysis in order to generate greater reliability and accuracy in the production flow modeling. In conclusion, the method presented excellent results when applied to BSW.
Self-Channeling in Proppant Pack in the Eagle Ford Shale Formation
Authors: Guerra J. , Zhu D. , Uribe Chacon J. , Luna Castillo E. 
Published: May 2017

Abstract
Well deliverability is directly related to the hydraulic fracture conductivity of the created fracture networks. There are several influencing factors on fracture conductivity, including fracture surface topography, mechanical properties, and proppant concentration. Fracture surface topography inherently defines the connectivity of cavities inside the fracture that serve as flow channels, and such flow channels are further enhanced by the presence of proppant. This paper presents a study considering the aforementioned phenomena, centered primarily on the effect of proppant concentration on the primary hydrocarbon-baring Unit B of the Eagle Ford Shale formation.
Laboratory experiments were conducted to investigate the effect of proppant concentration on fracture conductivity for Eagle Ford Shale samples. The test samples were obtained from outcrops at Antonio Creek, Terrell County, Texas. A 100-mesh sand was utilized, as it is representative of the industry practice in the region. Fracture conductivity measurements were conducted by flowing dry nitrogen at varying closure stress stages. Ancillary measurements included Young's Modulus and Poisson's ratio obtained by a tri-axial compression test. The Brinell hardness number was measured by an indentation test, and fracture surface topography was obtained using a laser profilometer.
Results show that the initial evenly distributed proppant concentrations were altered during the process of measuring fracture conductivity, yielding a final proppant distribution that partially occupied the fracture surface. The remaining surface area was absent of proppant and served as channels of high conductivity relative to the areas occupied by proppant. It is believed this behavior occurs in field operations, especially under conditions of varying gas flowrates during production. Additionally, this work suggests the possibility of an optimum initial proppant concentration that can result in the highest channeling behavior for a particular fracture surface.