bluuebunny/crossref_metadata_2025 huggingface dataset:
A Practical Numerical Approach for the Determination of Flow Contribution of Multi-Zones Wellbores
Authors: Tarom N. , Hossain M.
Published: May 2017

In these downturn oil price occasions, the establishment of a numerical model may become a reward in the continually on-screen tracking of the challenging issues such as evaluation of zones flow contribution; investigation of alternative methods in lieu of well interventions and prediction of wellbore temperature profile in the operation of multi-zones producing wellbores.

The new approach is based on energy, mass and momentum balance equations. The study briefly describes calculation of overall heat transfer coefficient which is based on the heat resistivity of different layers around a wellbore as well as the heat difference between wellbore and surrounding ground. A simplified numerical model is developed based on the overall heat transfer coefficient which accounts all modes of heat transferring mechanism. The model has been designed to predict wellbore temperature profile along a multi-zones production wellbore. The model explores wellbore temperature profiling both for single-phase and multi-phase production scenarios.

The proposed model has been run for the prediction of wellbore temperature profile for a published oil producing well perforated along three different intervals with the contribution of all intervals in the production. Predicted temperature profile is successfully applied for the investigation of flow contribution of each layer considering key thermal characteristics of single- and multi-phase fluid flow along the wellbore. The predicted temperature profile has been compared with the real data; and a good agreement is demonstrated. This is important as it demonstrates that the proposed model can predict wellbore temperature distribution on a real-time basis to continuously monitor downhole temperature without performing well intervention or installing mechanical tools.

Also, to explore the impact of flow rate and production string size on the wellbore temperature profile, sensitivity analyses have been carried out. It has been found that both flow rate and production string size may have a significant influence in the prediction of wellbore temperature profile. The major conclusion of sensitivity analysis of this study is that the higher production rates and smaller tubing sizes results a higher wellbore and wellhead temperature, which can be as a consequence of friction effect along the producing string.

The novelty of this study is to develop a governing equation as well as to develop a computer simulator for evaluation of wellbore temperature and flow profiles along multi-zones producing wellbores both accurately and quickly. As a result the study may turn aside the necessity of performing well intervention and downhole sensors installation which may significantly reduce well intervention risks and costs.
Five Years of Drilling with Casing in Argentina and Bolivia. Lessons Learned from the Field
Authors: Espinosa C. , Codega D. , Caglieri A. , Grill S. , Guttner H. , Roldan C.
Published: May 2017

Drilling with Casing (DWC) has been used in over 500 strings in the last 5 years in Argentina and Bolivia. The objective of this paper is to summarize the experiences and share the lessons learnt in those years from the perspective of casing connections manufacturer.

Within this paper several cases where drilling with casing technology has been used in Argentina and Bolivia. For each case there will be an explanation of the drivers behind the use of the technology, the challenges that arose during the field implementation and the lessons learned. Special attention will be given to the casing connections, the tools and services required and the limitations.

In Argentina and Bolivia drilling with casing has been used in extensively, in mature fields and shale applications. In all cases the objective was to reduce cost and improve efficiency during drilling. However the drivers where not always identical, in some cases the technology aimed to overcome drilling difficulties as wellbore stability and circulation loss; in others reduce NPT and increase efficiency.

The analysis of the experiences with drilling with casing technology indicates that there are two critical stages for the project: engineering and field operation. In the first, the analysis of fatigue, torque and buckling shall be done properly to reduce risks and hazards, being fatigue the less known and more difficult to assess. Regarding the second, the experience shows that improper handling and use of connections could lead to sudden and unexpected failures compromising the project sustainability. The results are summarized in a list of recommendations.

The experiences from the field have led to the development of specific tools and services aimed to extend the benefits of the technology to other areas. Furthermore, the data collected will shape the design of next generation of casing connections.

A guideline to select and operate casing connections in drilling with casing applications based on extensive field experience.
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

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

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

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

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

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

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

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

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

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

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

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.
A Fluid Structure Interaction Model for Hydraulic Fracture Simulation on Vaca Muerta Argentina Shale Formation
Authors: Alderete I. D. , Sosa-Massaro A. , D'Hers S.
Published: May 2017

Vaca Muerta Formation in Neuquén Basin, Argentina, is one of the great worldwide promises given its potential as a non-conventional reservoir. Because of the intrinsic heterogeneity and low permeability, hydraulic fracturing is a required operation to stimulate the reservoir for better production. Simulation becomes a desirable tool to make fractures more efficient and get predictable outcomes. For this purpose, a 3D finite element analysis is performed using ADINA software to model reservoir response during the hydraulic fracturing process.

This iterative, fully coupled model uses fluid structure interaction (FSI), porous elastic media and stratified materials with transversely isotropic (TI) properties. The allowed fracture distribution is proposed beforehand. A cohesive model is added via non linear springs placed along the fracture proposed path. Material models are calibrated using data from well logs and microseismics taken from one well located in the field. All the information obtained from that well is then filtered for a particular region of interest in depth, determined by the mechanical properties observed.

Regarding the calculation procedure, as initial condition for the stimulated reservoir volume (SRV) the stress strain state measured in the field is adopted. Then hydraulic fracture process is simulated pumping fluid through punched holes and then fracture opening is analyzed, based on nodes displacement along the proposed path, to characterize fracture's opening and extension. The resulting state of stress developed after the fracture is updated at every calculation step. Key information such as resulting pore pressure and effective stresses can be easily computed along the fracturing process.

Once obtained results are compared to analytical solutions and experimental data obtained from fractures performed in similar soil conditions with good agreement. The developed model can tackle a variety of reservoir volumes, considering stratification, geomechanical properties, fracture fluid, fracture paths and the initial state of stress. Natural cracks can be added in a rather simple fashion by adding fractures to the proposed distribution with adequate fracture strengths.
Reduction of Opex Costs and Increase of Oil Production by Means of Production Deferment and Pump Failure Prevention with a Cost-Effective Well Monitoring System
Authors: Armacanqui Samuel , Eyzaguirre Luz , Lujan Cesar , Tafur Yeltsin , Marticorena Harol , Rodriguez José , Paccori Hancco , De La Cruz Ruben , Yataco Sheyla , Sueldo Freddy , Cuestas Francis
Published: May 2017

A system of well monitoring in real time was developed, that is cost-effective and reliable. It allows the the obtained the real time data gattering.

Among the advantages of this system is the low price and effectiveness; as it uses low cost electronic components and an inexpensive communication network. The main electronic components used, are the Arduino controller and the wireless information transmitter using the free bandwidth in the world: 2.4GHz, which allows programming a more effective communication network (ZigBee Network); the power supply is based on photovoltaic cells (5V). The ZigBee Network Technology achieved its goal of keeping all interconnected points. The limited range of the transmitters (1500m) was overcome by the use of interconnected network points, which can build a grid to cover the entire field. The tested prototype was composite of four points in a transmition station – simulating a control room

The system is based on good quality and low cost equipment, that aims to reduce the production deferment and artificial lift equipment failures; by the implementation of a system that generates alerts according to the monitored parameters.
Hybrid Method with a Probabilistic Approach to Estimate Reserves in Mature Fields
Authors: Cervantes Bravo Reynaldo J. , Savioli Gabriela , Estrada José
Published: May 2017

The objective of this work is to present a novel methodology – Hybrid Method - to estimate reserves and resources in mature fields. The Hybrid Method consists of combining the probabilistic reserve estimation by volumetric method with the Arps´ decline curve analysis, also including a probabilistic approach. The understanding and managing of uncertainties in reserves and resources estimation are two of the most important problems in the oil industry, because the final figures might add value to the capital of a company and might influence the economy of a country.

The best way to deal with uncertainties in hydrocarbon in place and EUR estimations is to assign a probability distribution function to each variable involved in the computation and to apply the Monte Carlo approach. The Hybrid Method starts with the estimation of reserves obtained by the probabilistic volumetric method including a drilling portfolio. Porosity, initial water saturation, area, net pay, formation volume factor are the main variables used. Three levels of reserves are obtained: 1P, 2P and 3P. Then, the Arp´s decline curve analysis is applied. A probability distribution function is assigned to the Arp´s curve parameters, "b" and "D". Again, three levels of production performance are obtained and the proved reserves 1P (base curve + drilling portfolio) are defined using the cumulative production principle. The final step consists of normalizing, correlating and integrating the two distributions independently obtained by the two methods in the 1P and 2P zones. In this way, a unique distribution function, its percentiles and the location of "boundary reserves 1P/2P" (minimum value to be considered proved reserves) are determined. The "boundary reserves 1P/2P" might differ from the PRMS definition (2011) [6], that uses 90 % certainty to classify 1P proved reserves.

The described methodology is applied to a mature field in Talara Basin (Perú) using the production history and average petrophysical properties from Pariñas Inferior and Mogollón formations. A portfolio of four infill wells is incorporated in the calculation. In this case, the Hybrid Method obtains a better estimation of reserves in mature fields through risk reduction of up to 80 % compared to traditional methods.

The results show that this methodology has a great potential to provide consistency, transparency and reliability to the financial decisions [13].
Assessing the Long-Term Energy Landscape Using a Global Energy Market Model
Authors: Aguilera R. F. , Aguilera R.
Published: May 2017

The objective of this paper is to estimate the long-term energy mix – i.e. the combination of resources including solids, liquids and gases that will satisfy energy demand to the year 2040 – with a Global Energy Market model (GEM). The GEM provides a close match of the historical energy mix dating back to the year 1850 and is then used to make forecasts for the future. Originally developed in 2007, the GEM was used to project the energy mix to the year 2030. In the present paper, the validity of the original projection is tested against the most recently available data.

The GEM estimates the fractional contribution of different primary energy sources to the global market. In total, there are six parameters that allow the GEM equation to give the best possible match of the historical energy mix. Using the estimated parameter values, the model can then be extended into the future, providing a reference case and alternative scenarios of the energy mix based on evolving unconventional, conventional and renewable resource quantities, costs, technologies, economic growth, population and policies.

The original GEM findings from 2007 forecasted a "2030 1/3 forecast", indicating that solids, liquids and gases would each occupy a third of the energy market in the year 2030. After further disaggregating the categories, it was found that liquids, mostly, oil would experience a declining market share by 2030 while natural gas would see a rapid rise. The share solids, mostly coal, was relatively flat by that time. Our new results show continued penetration of natural gas in the energy mix – a result consistent with efforts to reduce carbon emissions.

Our proposed paper is novel in that it uses the most recent statistics of the last 10 years on consumption of different energy sources to verify the accuracy of the original GEM projections carried out in 2007. Once the results are proven reasonable, new scenarios are developed with an extended time horizon to the year 2040.
Evaluation of Water Oil Relative Permeability of Fractured Rock under Variable Conditions of Hydrostatic Effective Stress and Capillary Number
Authors: Restrepo A. , Lopera S. H. , Diez K.
Published: May 2017

In the study of fractured systems petrophysics, the concept of relative permeability is of primary importance as it integrates into a characteristic curve, the net effect of complex interactions between matrix, fracture and fluids as a function of the state of saturation. In most practical applications, this curve is assumed invariant to the state of stresses and / or to the relative magnitude of viscous and capillary forces, normally represented by the capillary number concept Nc. In coupled simulation schemes, some approaches incorporate geomechanical effects to petrophysical attributes such as absolute permeability, porosity, fracture width and fracture permeability and others; incorporate variable capillary number to the relative permeability functions. In a practical sense, the assumption of invariant Kr with the stress and / or the capillary number actually simplifies computational requirements but can underestimate known physical effects that variable stress regime and variable viscous-capillary forces field induce over multiphase flow and of special relevance in the context of naturally fractured reservoirs subject to fluids injection and production.

In this work, results of water-oil relative permeability curves, measured over a single fractured Berea core by the unsteady state JBN method, with variable hydrostatic effective stress and capillary number are shown. The aim of the present study is to advance towards the prediction of complex dynamics in systems were matrix-fracture deformation occur due to stress changes, and variable flow regime exist as a function of relative variations of the field of viscous-capillary forces across the reservoir. The methodology is based on the exploration of the variations of Corey relative permeability parameters with both hydrostatic effective stress and capillary number outlining that literature reports studies about the independent effect of these two variables but not of its combined effect.

Results to date indicate that the features of relative permeability curves of fractured rocks (e.g. ranges of mobile saturation, curvature, endpoints) get modified when changes on the effective hydrostatic stress, the capillary number or both are induced. It is herein proposed, that the degree and configuration of the variation of the curves with respect to a reference curve is a function of the level of flow transfer between the matrix and fracture which in turn is determined by the relative incidence of the capillary, viscous and deformation effects over both domains. Further phases of the investigation shall include additional variables such as anisotropic stress regime, other types of fractures and wettability conditions towards the derivation of empirical correlations for Kr prediction.
Successful Introduction of the First Worldwide 30 Casing while Drilling Job Saves 1.31 Days in an Exploratory Well in Shallow Waters, Mexico
Authors: Luna Gonzalez O. , Van Balen A. , Bavidge M. , Mafla J. , Karimov J. , Hurtado Cardenas P. , Karrer C. , Sotelo Fonseca M. , Gil Rodriguez P. , Mora A. , Noguez M. , Gomez G. , Garcia Lopez J. R. , Zamudio Lopez L. A. , Perez Cabrera J. C. , Gomez Tapia M. , Perez Ibarra R. , Olcese F. , Carranza J. A.
Published: May 2017

In exploration wells in shallow waters of Mexico, the challenge of reducing drilling time and enhancing efficiency of well construction had become a problem on a daily basis. The continued use and success of Casing while Drilling (CwD) led the operator and service companies to embark upon a more ambitious project. Using the learning curve of previous 20″ CwD conductor sections, the first 34″ PDC drillable drill bit was designed and the first Casing Running Tool (CRT) for 30″ casing was utilized. These tools were used to apply the technology in the conductor sections of wells targeting Mesozoic formations.

A technical feasibility study was performed by the operator and service companies involved to analyze the viability of executing this whilst creating new products. This saw the implementation of CwD using 30″ casing, an integral drilling system using casing as the drill string and a PDC drillable bit that allows drilling and casing of the section to take place simultaneously and eliminates the need to assemble a 36″ drilling BHA and, subsequently run casing. Once the CwD BHA (Casing + Drillable drill bit) reaches the final depth of the section, the hole is already cased and ready to cement. This challenged the service companies' engineering departments to develop the custom made tools for the application.

In the first well, the original plan was to drill the 30″ section using a 36″ roller cone bit, drilling from sea bed (+/-78m) to 250 mts. This was the candidate well that the operator chose to utilize an ″unconventional″ drilling system to ensure reaching TD in a single run prior to cementing the casing.

The 30″ × 34″ conductor section was drilled and cased at a depth of 256 meters, drilling a total of 178 meters with the PDC drillable drill bit (4 blades + 19 mm cutters) in 9:52 hrs., with an average rate of penetration (ROP) of 18.04 m/hr., and then preparations for cementing the 30″casing began. This entire operation represented a 26.3% time reduction compared with a conventional drilling operation

This document will show the methodology and technology used in Mexico Marine Exploratory fields to reduce and mitigate the risk of not setting the casing at TD, focusing on the pre-planning stage, proper bit selection, Torque & Drag (T&D) analysis, casing fatigue life analysis and the use of new technology with a high success ratio on the operations in order to add value and ensure the customer' satisfaction.
In Vitro Culture of Heuchera villosa ‘Caramel’
Authors: Zhao Hua Q. , He Qing H. , Song Li L. , Hou Mei F. , Zhang Zhi G.
Published: May 2017

The procedure for Heuchera villosa ‘Caramel’ propagation was investigated, which involves shoot regeneration, rooting of regenerated shoots, and acclimation of regenerated plantlets. Petioles, as explants, were cultured on MS medium supplemented with 1-naphthylacetic acid (NAA), benzylaminopurine (BA), thidiazuron (TDZ) and callus formed on all media. Shoots were observed to proliferate from callus on media with BA and NAA, whereas no shoots regenerated on media with TDZ and NAA. On media containing 0.5 or 1.0 mg·L−1 BA in combination with NAA, the regenerated shoots showed severe hyperhydricity, whereas on media containing 0.1 mg·L−1 BA in combination with NAA, the regenerated shoots grew normally. The highest shoot induction rate, 90.6%, was obtained on media containing 0.1 mg·L−1 BA and 0.01 mg·L−1 NAA. The effects of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and NAA on rooting of H. villosa ‘Caramel’ was explored. The highest rooting rate (95%) was obtained on 1/2 MS medium containing 0.2 mg·L−1 NAA. In the subsequent acclimation experiments, about 85% of rooted plantlets survived and grew normally.
Genome Size Variation in Elms (Ulmus spp.) and Related Genera
Authors: Whittemore Alan T. , Xia Zheng-Lian
Published: May 2017

Elms (Ulmus spp.) are iconic street and landscape trees, but their use is currently limited by susceptibility to disease, especially Dutch elm disease (DED). Improved access to disease-resistant germplasm will be of great benefit for ongoing breeding and selection programs, but these programs have been limited historically by uncertain relationships among Ulmus species, especially the North American species and their putative Old World relatives. Estimates of genome size from 28 species representing both subgenera of Ulmus (subg. Ulmus and subg. Oreoptelea) and six species in the related small genera Zelkova, Hemiptelea, and Planera were estimated using flow cytometry. Genome-size estimates were calibrated using seven elms with known chromosome counts. Results strongly supported the subgeneric classification of Wiegrefe et al. Monoploid genome size was found to be quite constant within the subgenera of Ulmus they recognized and within the small genera, and polyploidy is uncommon in these plants. However, there are consistent differences in genome size between the subgenera of Ulmus and between them and the smaller genera, and these differences can be used to place species in their proper taxon, knowledge which can be useful in identifying disease-resistant germplasm that may be compatible with Ulmus americana and other North American taxa. Two Asian species that have sometimes been considered to be related to North American species now placed in subg. Oreoptelea were tested. The Himalayan Ulmus villosa has a much smaller genome than either of the subgenera, indicating that its relationship with other elms is rather remote. It may be a source of novel genes in Ulmus, but our results indicate it is not close to U. americana or other New World species. In contrast, results from the rare Chinese species Ulmus elongata support its placement in subg. Oreoptelea. It is the only close relative of the North American elms that is native to Asia, where DED is believed to have originated, and its response to DED infection should be evaluated.