bluuebunny/crossref_metadata_2025 huggingface dataset:
(Des)Conexões Estado-Sociedade no Brasil: Um Estudo Sobre a Experiência de Construção de Cisternas no Semiárido
Authors: Cordeiro Neto José Raimundo , De Andrade Jackeline Amantino , Medeiros Marinheiro José Emanuel
Published: October 2017

Renovar a relação Estado-Sociedade, no Brasil, tem sido assunto em pauta nas últimas décadas. Nesse debate, inserem-se perspectivas teóricas como a Governança Pública e a Gestão Social, com suas devidas particularidades e algumas convergências. Simultaneamente, experiências consideráveis têm sido empreendidas, no país, através de formas colaborativas de gestão entre agências públicas e outros atores sociais. Abordando uma experiência dessa natureza, no âmbito da política de segurança hídrica no Semiárido brasileiro, este trabalho utilizou um design de pesquisa qualitativa. Foram empregados dados documentais e entrevistas, produzindo as narrativas para a análise realizada. Como resultado, procura-se evidenciar e discutir formas renovadas de gestão, forjadas na experiência acessada, destacando o provimento de soluções coletivas mediante papel ativo de famílias e organizações locais. Assinala-se, porém, a permanência de restrições, como a tendência de, frente às múltiplas lógicas de ação, contornar problemas decorrentes por mecanismos que inibem maior engajamento cívico.
Estimation of Foam–Flow Parameters for Local Equilibrium Methods by Use of Steady-State Flow Experiments and Optimization Algorithms
Authors: de Araujo Cavalcante Filho Jose Sergio , Delshad Mojdeh , Sepehrnoori Kamy
Published: October 2017

Foam has been successfully used in the oil industry for conformance and mobility control in gas-injection processes. The efficiency of a foam-injection project must be assessed by means of numerical models. Although there are several foam-flow models in the literature, the prediction of foam behavior is an important issue that needs further investigation. In this paper, we estimate foam parameters and investigate foam behavior for a given range of water saturation by use of two local equilibrium foam models: the population balance assuming local equilibrium (LE) model and the University of Texas (UT) model. Our method uses an optimization algorithm to estimate foam-model parameters by matching the measured pressure gradient from steady-state foam-coreflood experiments. We calculate the effective foam viscosity and the water fractional flow by use of experimental data, and we then compare laboratory data against results obtained with the matched foam models to verify the foam parameters. Other variables, such as the foam texture and foam relative permeability, are used to further investigate the behavior of the foam during each experiment. We propose an improvement to the UT model that provides a better match in the high-quality regime by assuming resistance factor and critical water saturation as a linear function of the pressure gradient. Results show that the parameter-estimation method coupled with an optimization algorithm successfully matches the experimental data by use of both foam models. In the LE model, we observe different values of the foam effective viscosity for each pressure gradient caused by variations of foam texture and the shear-thinning viscosity effect. The UT model presents a constant effective viscosity for each pressure gradient; we propose the use of resistance factor and critical water saturation as a linear function of the pressure gradient to improve the match in the high-quality regime, when applicable.
Enhancing Cement Integrity in Steam Injection Applications with High Temp Swellable Technology
Authors: Clark Travis , Davis Tim , Hance Derek
Published: October 2017

A critical design component on any steam injection project is to ensure steam containment. Loss of steam containment is not only a safety hazard, but also leads to poor well performance. Large changes in temperature have always been challenging to maintaining cement integrity not only during temperature ramp up, but certainly over the life of the well. Using high temperature swellable technology as part of the design for containment has proven to be highly effective.

In the design of a well, there are multiple casing strings, each with containment criteria and challenges. Challenges typically are due to difficulties in placing the cement and uncertainties on borehole shape. For years swellable packers have been used in conjunction with cement to overcome these challenges where cement alone has a low probability of providing successful containment. These challenges become more difficult in steam applications. Advancements in packer design and elastomer technology has led to the development of packers that can be run in casing designs which will encounter temperature up to 575°F (302°C). During the well design, critical containment areas are reviewed and consideration for the inclusion of a high temperature swellable packer is performed.

An operator of a cyclical steam injection project typically has seen steam at surface within days or weeks after initial heat up of the well. This results in additional steps to operate, maintain, and report on the well. High temperature swellable packers were piloted over a selected number of wells. It was found that wellhead pressure on cemented annuli was eliminated or significantly reduced after the first cycle of steam injection. The practice of including the packers now is used on every well and success is still being observed after multiple cycles of temperature. This reduces safety hazards as well as improve performance of the wells.
Phenomenological Correlation of Pressurization/Depressurization Hysteresis of Stress-Dependent Porosity and Permeability of Shale Reservoirs
Authors: Civan Faruk
Published: October 2017

This paper presents a theoretically rigorous correlation of the effect of poroelasticity on pressurization/depressurization hysteresis of stress-dependent porosity and permeability of shale reservoirs. Naturally fractured shale formations are characterized as a matrix-fracture system. The constituents of this model are individually described by their own stress-dependent properties which are then coupled to determine the overall stress-dependent response of the shale system. This model accounts for the deformation, transformation, deterioration, and collapse of the shale pore structure during pressurization and depressurization processes and their effect on the porosity and permeability of shale reservoirs. The comprehensive model developed in this study is then validated by means of the experimental data gathered by testing of samples from various shale and sandstone reservoirs. The phenomenological parameters of the shale and sandstone samples are determined for best match of the experimental data. The data analyzed in this study indicates that pressurization/depressurization hysteresis has a significant effect on the stress-dependent porosity and permeability of shale reservoirs. The model developed in this paper can describe the stress-dependent porosity and permeability of shale rock more accurately than the commonly used empirical correlations.
Detecting Poor Cement Bonding and Zonal Isolation Problems Using Magnetic Cement Slurries
Authors: Nair Sriramya D. , Patzek Tadeusz W. , van Oort Eric
Published: October 2017

There has been growing interest in the use of magnetorheological fluids to improve displacement efficiency of fluids (drilling fluids, spacer fluids, cement slurries) in the eccentric casing annuli. When magnetic particles are mixed with the cement slurry for improved displacement, they provide an excellent opportunity for sensing the presence and quality of cement in the annulus. This work focuses on using sophisticated 3D computational electromagnetics to simulate the use of a magnetic cement slurry for well cement monitoring. The main goal is to develop a new tool, which is capable of locating magnetic cement slurry that is placed behind a stainless steel casing. An electromagnetic coil was used to generate a magnetic field inside the borehole. It was found that when a current was passed through the electric coils, magnetic field lines passed through the stainless steel casing, the cement annulus and the rock formation. Three sensors were placed inside the cased borehole and the magnetic field strength variations were observed at these locations. Various factors that have a significant influence on zonal isolation were considered. These include, effect of debonding between casing and cement annulus, effect of changing annuli thickness, influence of a fracture in the rock formation, effect of changing magnetic permeability of cement and finally influence of annuli eccentricity. Based on the results shown in the paper along with the next generation of supersensitive magnetic sensors that are being developed, the magnetic approach appears to be a viable alternative for evaluating the quality of the cement annulus to ensure good zonal isolation.
Reaction Rate of a Novel In-Situ Generated HCl Acid and Calcite
Authors: Arslan Emre , Sokhanvarian Khatere , Nasr-El-Din Hisham A. , Shimek Nicole , Smith Kern
Published: October 2017

A new in-situ generated HCl acid was developed to overcome the fast reaction rate and high corrosion rates of 15 wt% regular HCl acidizing system. The objectives of this work are to: (1) examine the reaction rate of the new in-situ generated HCl with calcite at 100, 150, and 200℉, and (2) compare the reaction rate of 15 wt% regular HCl with the new in-situ generated HCl.

The rate of the reaction of 15 wt% HCl and the new in-situ generated HCl was measured using the rotating disk apparatus (RDA). Calcite disks were used with the specifications of 1.5 in. the diameter and 0.65 in. thickness. The effects of disk-rotational speed (200-1,200 rpm) and temperature (100-200℉) were investigated. Calcium concentrations were measured in the samples collected from the RDA, which were used to calculate the rate of dissolution. The disk surface after the tests was analyzed using Scanning-Electron-Microscope–Energy-Dispersive Spectroscopy (SEM-EDS).

Experimental results showed that the rate of dissolution at 100 and 150°F was controlled mainly by the rate of mass transfer of the acid to the surface. By increasing the temperature to 200℉, the overall rate of reaction for the in-situ generated HCl was mass transfer limited up to 800 rpm and surface limited above 800 rpm. Based on the dissolution rate results, the diffusion coefficient, the activation energy, and the reaction rate constant at 100, 150, and 200°F were determined for the new developed in-situ generated HCl and were compared to 15 wt% regular HCl.

This study will assist in developing a more cost-effective and efficient design of acid treatments through a slower reaction rate of the in-situ generated HCl. This new in-situ generated acid system reacts slower and more efficient compared to regular HCl in carbonate and sandstone reservoirs.
Challenges of Delivering Capital Projects in Fast Growing Indigenous Oil and Gas Company NOC: The SEPLAT Experience
Authors: Oladipo Adekola
Published: October 2017

The challenges facing indigenous oil and gas producing companies operating in the Niger-Delta are enormous especially during periods of supply glut with its resultant low crude oil prices. This paper identifies the key issues limiting the effectiveness of project delivery in indigenous oil and gas companies in the Niger-Delta and the attendant impact on the value to investment ratio. It then proffers practical and cost effective solutions that will mitigate against the erosive impact of these challenges.

The key issues limiting the effectiveness of project delivery in all the cases studied resulted in poor project delivery with significant project value erosion. Results showed that optimal value was not derived because of poor project phasing occasioned by a desire for an accelerated payout. In most cases the funding for such capital projects was sourced from financial institutions as loans with high interest rates. This urgency for a quick cash-out leads to poor Project Management practices and processes in most of the cases reviewed.

The critical success factor(s) of the projects were also evaluated using novel success screening criteria customized in-house for each project. Long term cost/Opex was also considered as one of the key factors. Some of the challenges experienced by indigenous national oil companies in capital project delivery as observed from this study are: variations due to improper scoping, poor project execution, poor stakeholder mapping and engagement, technical and technological limitations, poor cost management and poor concept selection and implementation resulting in high maintenance cost etc.

A new effective project delivery model was thus developed for all fast-growing indigenous oil and gas companies in the Niger-Delta and it has been proven from the studies to guarantee good cost savings (cost improvements of more than 10%) while ensuring that project delivery deadlines are met (reduction in project execution schedule by up to 15%). Other proven benefits of this model are: Improved Plant Availability and Reliability, Elimination of pre-mature failures, reduced HSE Risk, reduced OPEX, delivery of quality project and eliminating re-works, Improved Partner Relationship and Increase in Production

For effective capital project delivery and guarantee of return on investment, Proper scoping, planning, robust technical challenge of capital projects (benchmarking of such projects will create great value and increase the overall profitability), Implementation of change management, proper roles assignment (RACI), documentation of lesson learnt/dissemination of information to all the relevant stakeholders must be in place. A new project management life cycle was developed specially for fast growing oil and gas producing companies.
Well Collision Avoidance - Separation Rule
Authors: Sawaryn S.J. , Wilson H. , Bang J. , Nyrnes E. , Sentance A. , Poedjonoand B. , Lowdon R. , Mitchell I. , Codling J. , Clark P.J. , Allen W.T.
Published: October 2017

The well collision separation rule presented in this paper is a culmination of the work and consensus of industry experts from both operators and service companies in the SPE Wellbore Positioning Technical Section (WPTS). This is the second of two papers and complements the first paper SPE 184730 which described the collision avoidance management practices. These practices are fundamental in establishing the environment in which a minimum allowable separation distance (MASD) can be effectively applied. A standardised collision avoidance rule is recommended, complete with parameter values appropriate to the management of health, safety and environment (HSE) risk, and benchmarks for testing it. Together, these should help eliminate the disparate and occasionally contradictory methods in use today.

The consequences of an unplanned intersection with an existing well can range from financial loss to a catastrophic blow-out and loss of life. The process of well collision avoidance involves rules that determine the allowable separation and the management of the associated directional planning and surveying activities. The proposed separation rule is based on the pedal curve method and is expressed as a separation factor, a dimensionless number expressed as a ratio of an adjusted centre to centre distance between wells divided by a function of the relative positional uncertainty between the two. The recommended values for the rule's parameters are based on a comparison of various industry models and experience. The relationships between key concepts such as separation factor, MASD and allowable deviation from the plan (ADP) are discussed, together with their interpretation and application. The dependency on the error distributions of the survey instrument performance models used to establish the tolerance lines is also discussed.

The consequences of implementing a standardised separation rule across the industry are far reaching. It influences slot separations, trajectories, drilling practices, surveying programme and well shut-in. It is shown how the MASD can be related to a probability of crossing and being on the far side, or wrong side of an offset well. It is shown why this qualification is required for safe drilling practices to be preserved. Examples are presented to help the reader validate the calculations and software necessary to perform them. The limitations of the methods are explained and areas are highlighted for further work. The methods outlined here, taken together with SPE 184730, if implemented will improve efficiency in planning and executing wells and promote industry focus on the associated collision risks when drilling. The WPTS is also supporting the current development of the API Recommended Practices for Wellbore Positioning (RP78). Mathematical derivations or references are shown for all the calculations presented in the paper.
Methodology to Systematically Reduce Uncertainty Assimilating Quantitatively 4D Seismic and Well Data in a Probabilistic and Multi-Objective History Matching
Authors: Rosa Almeida Forlan La , Davolio Alessandra , Schiozer Denis José
Published: October 2017

History matching (HM) is a complex process that aims to increase the reliability of reservoir simulation models. HM is an inverse problem with multiple solutions that calls for a probabilistic approach. When observed data are integrated with sampling methods, uncertainty can be reduced by updating the probability density function (pdf) of the attributes. This work presents a practical methodology to systematically reduce uncertainties in a multi-objective probabilistic assisted history matching, integrating well and 4D seismic data (4DS) quantitatively. The pdf update goes through an iterative process. The pdf of the current iteration is combined with the pdf generated using the best-matched models to generate the posterior pdf. The multiple local objective functions (OF) are evaluated independently, allowing the identification of OFs that indicate the requirement of re-parameterization. This quantitative process was applied in two phases: (I) using only well data to constrain the models; (II) adding 4DS data. The methodology was successfully validated against a benchmark case of medium complexity, with the history-production data generated at fine scale (reference model). The proposed methodology reduced uncertainties for the majority of attributes, achieving the highest probable levels similar to those of the reference values. The identification of objective functions that restricts the match allowed improving of the parameterization employed, by locally adding probabilistic perturbations to the petrophysical realizations. The method efficiently achieved multiple matched simulation models, with all (87) local objective functions within the defined tolerance range. Each iteration increased the number of matched models, demonstrating good convergence. The uncertainties were reduced gradually, avoiding premature level elimination (minimizing convergence at an incorrect solution). In both phases, the matched simulation models presented similar production forecasts to the reference model. The 4D seismic data were included regionally with an acceptable increase in computation time. The quantitative incorporation of 4D seismic data generated models that forecasted production with less variability than models generated without 4DS data. This was expected as for this study, 4D seismic data provided perfect information.
New Wireless Acoustic Telemetry System Allows Real-Time Downhole Data Transmission through Regular Drillpipe
Authors: Hawthorn Andy , Aguilar Sergio
Published: October 2017

One of the key enablers for the huge advancements in oil field drilling has been the ability to access downhole data in real-time to facilitate decision making. It is hard to imagine wells being drilled now that do not have even a basic Measurement While Drilling (MWD) tool in the Bottom Hole Assembly (BHA). The huge advancements in geosteering and the development of highly deviated and horizontal drilling absolutely necessitate access to real-time downhole data.

However as wells have become more complex both onshore and offshore the actual amount of time spent on bottom drilling has significantly decreased as a percentage of total well construction activities. Some operators have seen that in the deepwater environment this may actually constitute less than 15% of total well time.(Blacklaw: SPE GCS Annual Drilling Symposium. April 2016). Casing, cementing and completion operations have not had the benefit of access to real-time downhole data. They have instead relied on surface measurements and associated modelling which has often been seen to deviate severely from what is actually happening downhole.

This paper will take a look at a new wireless acoustic telemetry system that has the ability to transmit right across the well construction operating envelope, and thus has the potential to give operators access to downhole data throughout all well construction operations. It is postulated that this access to data has the potential to inprove efficiency, limit non production time (NPT) and improve the safety of operations from spud through production.
Repeatable Steady-State Foam Experimental Data and Investigations of Foam Hysteresis in a Sand Pack
Authors: M'barki O. , Ma K. , Ren G. , Mateen K. , Bourdarot G. , Morel D. C. , Nguyen Q. P.
Published: October 2017

The repeatability of steady-state foam experiments in porous media had been a major concern due to either alterations in core petrophysical properties or the impact of trapped gas. Trapped gas is an important cause of history-dependent foam behavior known as foam hysteresis. The removal of trapped gas generated in a previous foam experiment can sometimes be difficult when one tries to restore the core for a subsequent experiment.

This paper presents systematic studies of steady-state foam behavior without hysteresis and foam transport with hysteresis. We developed a procedure to restore a sand-pack system after a foam flood, which ensured that every foam experiment started with the same condition of the sand pack saturated with 100% surfactant solution and ruled out the impact of surfactant adsorption or gas trapping. An experimental design composed of 24 steady-state foam core floods were carried out and the local pressure drops were measured and correlated with varying phase (gas and water) velocity and foam quality. Next, two groups of foam hysteresis experiments were conducted by varying either the foam quality or the total fluid velocity.

The results showed that the repeatability of the experimental data was excellent in the hysteresis-free experiments. In addition to the steady-state data obtained in traditional high- and low-quality flow regimes, we have also identified a transition to highly viscous foam where the pressure gradient increased significantly from the entrance to the exit of the sand pack at steady state. This transition has only been observed with relatively low foam qualities and high liquid velocities. Multiple pore volumes of injection before foam reached a steady state in most of the experiments were observed. Various possible reasons, such as the requirement of minimum pressure gradient and the homogeneity of the system, are discussed. In the subsequent study of foam hysteresis, the first group of experiments showed that the final steady states of foam apparent viscosity at fixed foam quality and total fluid rate were generally repeatable regardless of initial state (phase saturations) of the sand pack in the high-quality regime; however, the initial state had a significant impact on the transient process before reaching a steady state. In the second group of experiments, the results indicated that foam hysteresis had a significant influence on the final foam steady state.

To our knowledge, it is the first time that such reliable and systematic data base for steady-state foam behavior in porous media without hysteresis was provided. This comprehensive data set in combination with foam-hysteresis data could therefore be used for foam-model evaluation and improvement with high confidence.
Achieving Directional Control and Rathole Elimination While Under-Reaming Depleted Formations with a Rotary Steerable System
Authors: Greenwood Jeremy A
Published: October 2017

An oil and gas operator in the Gulf of Mexico planned to drill a deepwater well section in one run by concurrently drilling and enlarging a 12 1/4- to 14 1/2-in. hole while deviating from 60 to 30° inclination and crossing expected depleted formations. At section total depth (TD), the rathole below the under-reamer needed to be eliminated to help ensure successful cementing of the liner. A bottomhole assembly (BHA) was designed to allow achieving these objectives in one run, and the field results obtained with the system are described.

The first step in determining the best BHA design was to compile drilling experiences through the target formations and perform a comprehensive review of all pertinent offset well information. Weaker zones had been encountered in the 12 1/4- × 14 1/2-in. section, and an at-bit reamer (ABR) had to be included in the BHA to allow the liner to be set on bottom of the section, rather than leaving an 85- to 135-ft rathole. Because the ABR placement in the BHA is between the bit and the rotary steerable system (RSS) tool, it was important to ensure directional control could be maintained in the section and make certain no interference existed between the ABR and the wellbore that could compromise control. Stabilization and placement of the under-reamer were crucial also to ensure the necessary directional performance was obtained without overstressing the BHA components, and extensive modeling was performed to optimize the design. Thorough hydraulics and torque and drag modeling ensured the BHA design could drill the depleted zone without premature activation of either reamer.

The detailed modeling and analysis of offset performance resulted in successfully drilling the section and opening the rathole in one run. The BHA was steered to the final desired angle and reached the section TD without incident and at the desired rate of penetration (ROP). Once the section TD was reached, the ABR successfully opened the 12 1/4-in. rathole to the desired 14 in., allowing the liner to be set 3 ft from bottom. This type of operation would normally require a separate dedicated hole-opening run. Using the new design eliminated the additional trip and the time necessary to open the hole, which was estimated at 56 hours.

A BHA solution was developed through detailed modeling that allowed the operator to not only maintain the steerability needed to achieve directional requirements with an ABR between the bit and the RSS while drilling depleted formations but also to concurrently perform under-reaming.
Smart Lost Circulation Materials for Productive Zones
Authors: Mansour A. , Ezeakacha C. , Taleghani A. Dahi , Li G. , Salehi S.
Published: October 2017

Lost circulation occurs when mud or cement is lost to the formation while drilling. Lost circulation has been a huge problem and may cause heavy financial costs in the form of lost rig time and mud fluid and in severe cases, well blowout with serious environmental and safety consequences. Despite extensive advances in the last couple of decades, lost circulation materials used today still have disadvantages such as damaging production zones, failing to seal the fractures or just sealing the fractures without strengthening the well. Here, we propose a new class of smart expandable lost circulation material (LCM) to remotely control the expanding force and functionality of injected LCM. Our smart LCM is made out of thermoset shape memory polymers and becomes activated by formation natural heat as well as electromagnetic waves if needed, hence it can effectively seal fractures’ width without damaging production zone and strengthen the wellbore. The activation temperature of the LCMs can be adjusted based on the formation temperature. We conducted a series of experiments using a HPHT particle-plugging apparatus (PPA) to measure the sealing efficiency of the smart LCMs as a proof of concept. Various slot disc sizes were used to mimic different size fractures in the formation. The API RP 13 B-1&2 have been followed as standard test methods to evaluate fluid loss in water based muds.
Modeling of CO2 Leakage from CCS into Overlying Formations - Quest CCS Monitoring Evaluation
Authors: Duer Jeff
Published: October 2017

Commercial-scale deployment of Carbon Capture and Storage (CCS) as a viable greenhouse gas emissions reduction technology requires that the CO2 be confidently contained in geological formations with no risk of groundwater contamination. To ensure containment is adequately monitored, an evaluation of what a potential leak could look like and how it can be detected is required. This paper is an example from the Quest CCS operation in Alberta, Canada.

Quest commenced operation in August of 2015 at a rate of 1 MT/year into two injection wells. After two years of operations, the project’s rigorous monitoring program has demonstrated that the reservoir is behaving as expected and no leaks have been detected. However, hypothetical leak paths have been investigated and modeled. Four scales of models have been used to evaluate the risks associated with the hypothetical leak paths and therefore on containment: (1) Geological structural models - Regional Static Model, Field Dynamic Model, (2) Legacy well - Well Brine Leak Path Model (3) CO2 Leakage - Injection Well CO2 Leak Path Model, and (4) Leak detection - Cooking Lake Model. The results of the modelling were used in the evaluation of the Quest project proposal, the current operating strategy, and the measurement, monitoring, and verification (MMV) plan.

The results of the leak path models demonstrate that the risk of a CO2 leakage from the Quest storage operation is very low. Regional modeling of the overburden confirmed that no leak pathways in the project area could be identified. Field level dynamic modelling demonstrated that injected CO2 is not expected to reach far field legacy wells, but the potential for elevated reservoir pressure displacing saline brine into usable ground water could be a risk if insufficient well count. The impact of a brine leak path was modeled and concluded to be negligible as the overlying under pressured cooking lake formation was concluded to be an effective pressure sink. As the injection wells have the highest pressures and concentrations of CO2 in the reservoir, despite excellent wellbore integrity, they are the most likely location for a theoretical CO2 leak path. It was both concluded that the buoyancy force was a very slow moving affect and that the cooking lake formation ultimately acts as a pressure sink. Therefore, the cooking lake was modeled to understand what pressure response could be expected and whether a leak into those formations could be detected. It was concluded that material leaks at the injection well would be differentiable from baseline pressure drift at the monitoring wells.
New Sand Screen Increases the Reliability of Sand Control in Water Injection Wells by Mitigating Common Failure Mechanisms
Authors: Charles Jack , Fipke Steven
Published: October 2017

The production of both fines and matrix sand into the well bore is a common problem in water injection wells due to transient pressure and flow events. Conventional sand control techniques do not manage these transient events effectively, and the reliability of the sand control can be compromised as a result.

In injection wells, a shutdown event results in a sudden stoppage of flow causing a surge which can result in powerful downhole pressure transient effects such as back-flow, cross-flow, and water-hammer. These effects can mobilize sand particles in the near-wellbore resulting in an influx of fine particles, screen plugging and erosion. Eventually, the accumulation of debris in the well can lower or block injection rates to the point where a water injector well must be repaired or replaced to maintain the injection volumes required for pressure maintenance and sweep in the reservoir.

A new, sand screen compatible completion was designed with an array of integral non-return valves (NRV) to address these challenges. This paper will present an overview of the product development with computation fluid dynamics (CFD) modeling, flow-loop and laboratory testing. Design considerations of any potential adverse effects of the new non-return valves, such as plugging and erosion, were studied extensively in lab tests on a series of valve designs. Non-return valve completions could have the benefit of increasing injection volumes and extending the life-cycle of water injections wells.
Partial Processing: Produced Water Debottlenecking Unlocks Production on Offshore Thailand MOPU Platform
Authors: Rawlins C. H.
Published: October 2017

An operator in the western Gulf of Thailand installed two water management Partial Processing systems on their D and E Mobile Offshore Production Unit (MOPU) platforms to increase oil production. Electric submergible pump (ESP) wells connect to each MOPU for primary gas-liquid separation. The produced liquids, at ~90% water cut, are piped to a dedicated Floating Storage and Offloading (FSO) tanker for water separation and oil storage. The separated water is pumped back to the MOPU for re-injection disposal. High volumes of produced water created bottlenecks at the MOPU separator and the MOPU-FSO transfer lines (both directions), which then limited oil production. Additionally, substantial energy is spent on fluid heating to prevent wax formation in the flow lines to the FSO. Much of this heat is lost to the bulk water phase. In 2016, a Partial Processing system was retrofit on each MOPU process facility for bulk removal and treatment of produced water. Water removed at the production manifold is treated and transferred directly to the injection system, thus bypassing the primary separation, transfer piping, fluid heating, and FSO storage facilities. Water debottlenecking increases oil production by 80% and reduces the in-field transfer volume by 62%. This Partial Processing project is a step-change in field economics, allowing a three-month payback. Field layout, water cut issues, and the Partial Processing solution are detailed. Partial Processing has increased revenue and reduced operating costs at the facility.
Comparison of Shale Oil Production Forecasting using Empirical Methods and Artificial Neural Networks
Authors: Suhag Anuj , Ranjith Rahul , Aminzadeh Fred
Published: October 2017

The objective of this work is to evaluate the efficacy of empirical models in forecasting oil production in shale reservoirs, bycomparing and analyzing their fit and effectiveness to our dataset. The following three modelswere considered: A Conventional Decline Curve Analysis (CDC), an Unconventional Rate Decline (URD) Approach, and a Logistics Growth Analysis (LGA) method. A comparative study is performed to evaluate the use of Artificial Neural Networks (ANN) for production forecasts and to reinforce the thinking that it is imperative to include physical parameters in mathematical models to predict accurateforecasts.

For this project, we used non-linear regression to fit empirical models to the dataset obtained from North Dakota Industrial Commission (NDIC). We evaluated the fit of modelswith the help of coefficient of determination. Physical parameters, such as porosity, saturation, shale volume, etc., and log data from sonic logs, gamma ray logs, etc., were selected as input to the ANN model andwere aided by Analysis of Variances (ANOVA).

Amongst the empirical models for shale play, URD method is the most commonly used since it is idealfor fractured reservoirs with extremely low permeability. URD model did fit the cumulative production profiles, but could not accurately fit the monthly production profile. The CRD approach was overallunsuccessful in generating accurate future production profiles. Values forecasted from the ANN show less than 10% error in estimation. The inclusion of physical parameters has proven to be extremely promising in the forecast production from fields that do not have sufficient history for statistical fitting.

Through aselection of physical properties from different sources, we have built an ANN model that fits with the production data in wells that have adiverse production history. Our work has shown the importance of including physical parameters into a process that was heretofore seen as a time series regression problem. In general, our new ANN-based method generated the best results.
Adaptive Homogenization for Upscaling Heterogeneous Porous Medium
Authors: Singh Gurpreet , Amanbek Yerlan , Wheeler Mary F.
Published: October 2017

One of the major objectives in the development of upscaling approaches is to reduce the computational costs associated with solving fine scale flow and transport problems in heterogeneous porous media. This is due to the availability of reservoir rock property data at fine spatial scales, such as facies distributions, obtained from geological models and field data from well logs. The data sets from each of these sources are themselves at different spatial scales which further adds to the computational challenge. The upscaling approach must not only accommodate these disparate data sets but also capture the flow physics accurately while maintaining computational efficiency. We present a novel upscaling approach which draws upon previous developments of two-scale homogenization (Amaziane et al., 2006) to obtain coarse scale properties in addition to dynamic mesh refinement using an enhanced velocity mixed finite element method (EV MFEM) (Wheeler et al., 2002). A transient region is defined where changes in saturation/concentration are above a chosen threshold compared to a non-transient region where these are relatively small. Since most of the recovery technologies employed in oil and gas field operations involve flooding the subsurface porous medium; as in the case of water-flooding, chemical or gas enhanced oil recovery (EOR), these aforementioned transient regions are usually restricted to much smaller subdomains of the entire reservoir domain. The computational efficiency is achieved by using coarse scale parameters, from numerical homogenization, in the non-transient region. Furthermore, the solution accuracy is preserved by using fine scale information only in the transient region. The numerical results section shows that our adaptive homogenization approach closely captures fine scale flow and transport features while maintaining a computational speedup of approximately 4 times for a variety of permeability distributions extracted from the SPE 10 comparative upscaling project (Christie and Blunt, 2001).
Fresh Water Neutral: Managing Water Use and Giving Back to the Environment
Authors: Greaves R. , Hartstein R. , Lincicome D. , Beck P. , Boothe M. , Olson K. E.
Published: October 2017

Southwestern Energy (SWN) is committed to offsetting our fresh water footprint by reducing fresh water use and replenishing any fresh water that is used, barrel for barrel, through conservation projects, i.e., "Fresh water Neutral". In 2013, thecompany launched the Energy Conserving Water (ECH2O®) initiative with the goal of becoming fresh water neutral in all operations within three years. SWN achieved this status in 2016 within each of the operating divisions across the company, thus meeting the program objective. This paper presents the challenges encountered and offers lessons learned.

The first step in the program was to create a small corporate team to investigate all aspects of the operational water life cycle, seeking to optimize fresh water use at similar economic returns compared with other projects. Successfully refining the approach to water management involved several key elements: 1) commitment from company leadership and support across all operations, 2) operational goals to progress the program, 3) accounting for all water used, 4) modification of completion designs, 5) increased use of alternative, non-fresh water, and 6) supporting research in groundwater protection and water treatment technologies.

Even though the process of optimizing water management aids in reducing fresh water needs, there continues to be a critical demand for the use of fresh water in operations. To offset this use, SWN has participated in conservation projects located in each operational area. The conservation projects are selected for the fresh water benefit they generate for the surrounding environment.

Becomingfresh water neutral in each operational division required several changes and improvements in everyday work practices. Over time, it also changed the mindset of water management across the company. Today fresh water use is viewed differently and there is an impetus to use alternative sources whenever economically and operationally feasible. Also, the conservation projects SWN has completed have created a sense of pride in our company's environmental approach and strengthened bonds with the communities where we work.

The continuing challenge is to remain fresh water neutral, while dealing with short-term changes that occur in operational pace and activity levels.
Modeling and Simulation of Transport Phenomena in Organic-Rich Marcellus Shale Rock Matrix
Authors: Goral Jan , Miskovic Ilija , Deo Milind
Published: October 2017

The growing worldwide energy demand has greatly stimulated the exploration and production of unconventional oil and gas resources. Because of the large amount of reserves, shale oil and gas is one of the most promising unconventional energy resources. Therefore, considerable efforts are being undertaken by many research programs to make this resource successfully and economically available. Understanding pore network evolution along with transport phenomena within shale rock matrix is an important issue. The constituents of shale rock matrix include organic matter, nonorganic matter, and pore network. It has been shown for shales that the majority of the pores are isolated from each other, with some evidence for certain pores to form individual systems not necessarily connected with each other. However, hydrocarbons could potentially diffuse through organic matter from one system to another, providing a potentially important production mechanism to supplement the more conventional pressure-driven flow through connected pore systems.

Here we present a comprehensive modeling and simulation framework, using digital rock physics (DRP), for diffusion flux analysis in organic-rich Marcellus shale rock matrix. First, three-dimensional (3D) models of the shale rock matrix are reconstructed from nano X-ray microscopy (nano-XRM) and focused ion beam scanning electron microscopy (FIB-SEM) images. Subsequently, the organic-matter-related and nonorganic-matter-related pores are separated from each other, which allow for the integrationof mineralogy and porosity for the most realistic transport phenomenamodeling and simulation in shale reservoir matrix. Second, anewly created 3D representation of the organic matter network is used as an input to model/simulate diffusion flux through the selected region of interest (ROI). Finally, the impact of obtained results on transport phenomena within shale is analyzed.

Results indicate that the organic-matter-related pore network strongly dominates over the nonorganic-related pore network within the investigated rock sample. This suggests a strong relationship between porosity and organic content. This creates possible flow pathway channels for the gas and/or liquid to migrate through organic matrix from one pore system to another. The size of the pore-organic matter systems and components, and the connectivity of thesesystems within the shale rock matrix, are key controls on the delivery of fluid from pore to fracture and then towellbore. Results presented in this study are aimed providing new insight into the effects of the matrix composition on transport phenomena in the example from the Marcellus Shale reservoir.
Balanced Scorecard and Strategic Map Applied to Portfolio Management
Authors: Luis Creus Fernando
Published: October 2017

In June 2014, the oil price began an unpredictable steep decline after more than three years of being over the barrier of the 100 USD/Barrel (Brent). By the end of that year, the commodity lost 43% of its market value, reaching at the beginning of 2016 a minimum value of 27.88 USD/Barrel (Brent). The purpose of this paper is not to explain the forces that determine the price of the crude oil, but the question is: How many companies were prepared in June 2014 to face a 75% reduction in the value of their projects? How many of them could be defined as resilient organizations, with the ability to "survive adversity and to thrive in a world of uncertainty?"1

There is a valuable bibliography related to Reservoir Management, defined as the process that "optimizes the interaction between data and decision making during the life cycle of a field".2 Nevertheless, this position assumes that the top management has already decided the group of projects to carry out. The first pillar is missing: how to build a portfolio that enables executives, given a specific scenario, to select the proper combination of projects and to truly execute the optimal strategy for the company. While Reservoir Management works on each project separately, Portfolio Management brings the systemic approach in "understanding and exploiting the interplay among both existing and potential projects"3

This paper put forward the Balanced Scorecard and the Strategic Map applied to Portfolio Management as the nexus between Portfolio and Reservoir Management, and as the tools that enable executives to select the best strategy to cushion market volatility and translate it into actions.