bluuebunny/crossref_metadata_2025_split huggingface dataset:
Furthering the Capabilities of Coiled Tubing Production Logging in Horizontal and Highly Deviated Wells: The Advent of Reservoir Saturation Logging in Southern Mexico
Authors: Bueno O. Jimenez , Nava A. F. , Leyva H. Hernandez , Ortega C. A. , Ramondenc P. , Fonseca S. Hassig , Fernandes R. A. , Rodriguez F. L. 
Published: September 2015

Abstract
A new solution to reservoir saturation logging in highly deviated and horizontal wells leverages a light system using coiled tubing (CT) equipped with fiber optics to overcome reach limitations and provide real-time acquisition of downhole reservoir information. The advantages of the methodology in terms of technical capabilities and efficiency have been demonstrated in wells in Mexico where acquisition of once-inaccessible logging information opened new avenues in the production management of the area.
The conveyance of logging tools via wireline cable or wired CT presents significant reach and pumping limitations in highly deviated or horizontal wells. The combination of a recent downhole module development and the use of lighter CT package equipped with fiber optics addresses these conveyance and operating challenges. The optical telemetry link supports real-time logging without the need for wireline surface equipment, and the new downhole module provides power to a wide range of logging tools, including the power-demanding reservoir saturation tools.
The lighter system overcomes weight limitations, and logging can be performed in any type of well profile. The new module significantly increases the voltage output from the downhole source to the logging toolstring, thus enabling the use of power-demanding components that were previously unusable with CT systems. It also extends the downhole operating logging time for traditional production logging tools by up to six times over that of previous methods. As the production of mature fields in Southern Mexico is gradually decreasing and water has become an increasing issue, operators in the area are currently performing major workover operations to rejuvenate the fields. This novel approach enabled acquisition of reservoir saturation data in several wells in which this information could not be acquired previously because of reach limitations. The newly acquired data enabled identification of bypassed hydrocarbons in those wells. With this information, the operator could selectively shut off the water-producing zones while opening new hydrocarbon-bearing ones, thus significantly reducing water production and prolonging the life of the wells.
The introduction of the innovative methodology not only significantly broadens the range of logging interventions that can be performed, it also enables accessing reservoir data that, in some cases, have been inaccessible for a long time, and which can be key to the optimization of production management of entire fields.
Rapid Data Integration and Analysis for Upstream Oil and Gas Applications
Authors: Cheung Chung Ming , Goyal Palash , Harris Greg , Patri Om , Srivastava Ajitesh , Zhang Yinuo , Panangadan Anand , Chelmis Charalampos , McKee Randall , Theron Mo , Nemeth Tamas , Prasanna Viktor K. 
Published: September 2015

Abstract
The increasingly large number of sensors and instruments in the oil and gas industry, along with novel means of communication in the enterprise has led to a corresponding increase in the volume of data that is recorded in various information repositories. The variety of information sources is also expanding: from traditional relational databases to time series data, social network communications, collections of unsorted text reports, and linked data available on the Web. Enabling end-to-end optimization considering these diverse types of information requires creating semantic links between them. Though integration of data across silo-ed databases has been recognized as a problem for a long time, it has proven to be difficult to accomplish due to the complexity of the data arrangement within databases, scarcity of metadata that describe the content, lack of a direct mapping between related entities across databases, and the several types of data represented within a database. In addition, there are large amounts of unstructured text data such as text entries in databases and document repositories. These contain valuable information on processes from the field but there is currently no method to convert this raw data to useable information. The Center for Interactive Smart Oilfield Technologies (CiSoft) is a USC-Chevron Center of Excellence for Research and Academic Training on Smart Oilfield Technologies. We describe the Integrated Optimization project at CiSoft which has the goal of developing a framework for automated linking of heterogeneous data sources and analysis of the integrated data in the context of upstream applications.
Permeability, Skin and Inflow Profile Estimation From Production Logging Tool Temperature Traces
Authors: App Jeff 
Published: September 2015

Abstract
Temperatures traces from multiple rates are used to estimate the production inflow profile and layer permeability and skin using a transient coupled reservoir/wellbore model. Production Logging Tool (PLT) temperature traces from two rates show heating of approximately 6–11 °F above the geothermal due to Joule-Thomson expansion of the reservoir oil. Production is single phase oil from a high pressure oil reservoir. Nonlinear regression was used to automatically adjust the layer permeability and skin values until the observation temperature traces from both rates were matched. History matching the temperature data provides a quantitative estimate of the skin and permeability within each contributing layer; this cannot be obtained from conventional pressure transient analysis which unless for highly specialized cases provides only a single value of permeability and skin. The production inflow profile is then constructed using the history matched layer permeability and skin values. In addition to the wellbore temperature profiles, temperature and pressure profiles within the reservoir will be shown which illustrate the relative impact of the reservoir permeability and skin on the wellbore temperature responses. Information on the coupled reservoir/wellbore model and the optimizer will be provided.
FLNG vs ‘Subsea-To-Beach’: A Study on the Critical Factors Governing Concept Selection in Deepwater Gas Field Developments
Authors: Beltrami Francesco , Olugbode Funmi , Subramanian Kartik , Barrero Alejandro 
Published: September 2015

Abstract
The objectives of this study are: (a) The investigation of the main technical factors affecting the preliminary design and cost estimation of a ‘Subsea-to-Beach’ subsea production system (SPS) and, indirectly, of a floating LNG (FLNG) offshore development; (b) The identification of the ‘key’ factors, seen as the real differentiators in the comparison between ‘Subsea-to-Beach’ and FLNG; and (c) how these ‘key’ factors relate to other decision factors (for example, economics, risks, and technology readiness).
The four (4) steps followed in this study can be summarized as follows: (a) Review of historical ‘Subsea-to-Beach’ developments associated to LNG production; (b) Definition of the study cases, including preliminary design and cost estimation (by means of a proprietary cost estimating tool); (c) Presentation of the cost estimates and discussion of the technical factors that affect them in the most relevant way; and (d) Discussion of the key differentiating factors with respect to areas of applicability for ‘Subsea-to-Beach’ and FLNG (where one of the two alternatives works best).
Offshore Membrane Deaeration as a Replacement for Vacuum Tower Deaeration - A Comparative Study
Authors: Van Pelt Stephen , Churman Holly 
Published: September 2015

Abstract
A membrane deaeration pilot study undertaken on seawater from an onshore seawater intake, successfully demonstrated removal of dissolved oxygen to less than 10 parts per billion without the use of chemical oxygen scavenger. To assess the commercial viability of adapting membrane deaeration technology to offshore oil and gas applications, a comparative evaluation of size, weight, capital cost, and operating cost for membrane deaeration versus conventional vacuum tower deaeration was performed.
The comparative evaluation considered membrane and vacuum tower deaeration technologies across a range of injection flow rates, from 30,000 – 250,000 barrels per day. Multidisciplinary engineering and design was conducted for each technology at specific injection flow rates within this range. Detailed 3D models, material take-offs, and weight reports were produced for each design. The capital cost study was prepared, with the goal to estimate direct field cost for installation of each technology. These costs were derived using quotes from vendors and installed cost norms for similar offshore installations. Operating costs were developed using quotes for consumables and estimations for power cost.
The comparative evaluation indicated that selection of membrane deaeration technology over conventional vacuum towers resulted in the following offshore facilities impacts: 60 – 70% dry and operating weight savings across the entire range of injection flow rates studied.30 – 60% total size savings, with increased savings at elevated injection flow rates.10% footprint savings from 125,000 – 250,000 barrels per day. The footprint of membrane deaeration is larger at small flow rates.
Selection of membrane deaeration technology over conventional vacuum towers results in the following offshore economic impacts: 10 – 15% direct field cost savings from 30,000 – 125,000 barrels per day. Direct field cost savings between 5 – 10% from 125,000 – 250,000 barrels per day, as economies of scale of vacuum towers begin to take effect.50 – 60% annual operating cost savings across the entire range of injection flow rates studied, based partially on an assumed cost per kilowatt-hour for offshore power generation.
This study accounts for parameters which have not been addressed in previous literature to date: Costs related to the installation of each deaeration technology on offshore topsidesImpacts on the entire topsides process due to selection of each deaeration technology (i.e., injection booster pumps, chemical injection facilities, etc.)
New Fast and Accurate 3D Micro Computed Tomography Technology for Digital Core Analysis
Authors: Katsevich A. , Frenkel M. , Feser M. , Huang Z. , Andrew M. , Case T. , Gu A. , Thompson W. 
Published: September 2015

Abstract
Micro Computed Tomography (micro-CT) of cores is an emerging technology that yields vital information about key rock and fluid properties at pore-scale resolution. Micro-CT imaging results presented to date are encouraging and indicate that this technology has the potential to revolutionize petrophysical analysis and reservoir engineering. The application of micro-CT in petroleum engineering requires reconstructed scan data to be of high and uniform image quality to enable reliable analysis during subsequent segmentation and numerical modeling. This is achievable in existing micro-CT systems using standard circular scan trajectories with non-exact filtered backprojection (FBP) reconstruction, but requires small cone angles to keep cone beam artifacts below detectable limits.
We describe the implementation and results of adapting an exact helical FBP reconstruction algorithm (the so-called “Katsevich Algorithm” or KFBP) and data acquisition scheme on a high-performance micro-CT system normally running in circular scan trajectory mode. Side-by-side comparisons of stitched circular scan trajectories with continuous helical scan trajectories on simulated and real rock core data show the throughput advantage of this modality for applications relevant for the petroleum industry keeping equivalent image quality to low cone angle circular scans. The analytical exact helical reconstruction can be performed in quasi-real time leading to instantaneous results. Simulated and experimental results indicate that an imaging throughput improvement of 2-5 times can be achieved employing KFBP-based exact helical reconstruction compared to the standard circle scan trajectory when imaging whole rock cores/plugs that are significantly longer than their diameter.
The New Reality of Hydraulic Fracturing: Treating Produced Water is Cheaper than Using Fresh
Authors: Barnes Christopher M. , Marshall Ryan , Mason John , Skodack Dave , DeFosse Grant , Smith Daniel G. , Foreman Scooter , Hanna Ty , Cecchini Michael 
Published: September 2015

Abstract
Simple, cheap, and reliable treatment of produced water will transform the economics and viability of unconventional plays. Produced water recycle not only creates options to minimize fresh water usage; in local areas it can take tens of thousands of water hauling trucks off the road and significantly reduce salt water disposal.
This is no pipe dream. A novel process based on a step-change in the application of chlorine dioxide chemistry has been proven to work and consistently generate frac-compatible fluid at several company facilities in Texas. The solution is an inline system that simplifies the operation, optimizes chemical consumption, and enables continuous on-the-fly treatment. Case studies over multiple years and greater than 18 million barrels used at the field level show that produced water is being recycled for less than half the equivalent cost of using fresh water.
Refracs- Diagnostics Provide a Second Chance to Get it Right
Authors: Leonard R. S. , Moore C. P. , Woodroof R. A. , Senters C. W. 
Published: September 2015

Abstract
The surge in unconventional completions over the last 10 years has created a substantial accumulation of previously hydraulically fractured wells that are candidates for hydraulic refracturing (refracs). As new plays are developed over time, refracs offer the opportunity to apply improved stimulation techniques to optimize well performance.
Maximizing new fracture network development is a key to successful re-stimulation of existing unconventional wells. Completion diagnostics are a valuable tool in determining the most cost-effective stimulation and completion parameters, part of the refrac optimization process. All of the major unconventional basins have seen significant design changes over time. Refracs allow the operator to capitalize on this continuous improvement in stimulation design. They also provide an excellent opportunity to add incremental production.
The dataset contains over 65 wells that were re-stimulated during the last 10 years. Stimulation and production information will be provided along with suggested refrac techniques. Several diagnostic case histories for Barnett Shale and Marcellus Shale wells will illustrate various successful approaches to the re-stimulation process. The data will be used to address observed diagnostic metrics.
Key parameters and diagnostic metrics will be defined and utilized for the candidate selection process, refracturing design, and post-refrac evaluation. This is the first macroscopic study of its kind where diagnostic and completion metrics are compared with performance metrics. The focus of this study is to compare the various captured metrics with the incremental estimated ultimate recovery (EUR) percentage gains from the refracs. Additionally, post-refrac production rates will be compared with the existing maximum monthly production. The results of this study should continue to be an excellent tool for further optimization in re-stimulation across North America.
Diagnosis And Characterization Of Cross Flow Behind Casing From Transient-Pressure Tests
Authors: Anisur Rahman N. M. , Bin Akresh S. A. , Al-Thawad F. M. 
Published: September 2015

Abstract
A reservoir system with two neighboring layers, the tested and the adjacent layers being separated by impermeable strata, is considered. Fluid may still migrate from the adjacent layer to the tested layer if the zonal isolation behind casing is compromised or flow channels exist in the vicinity. A method is presented to diagnose the fluid contribution to the tested layer from the adjacent layer, and to quantify the transient rate of cross flow by utilizing the transient-pressure data.
During transient tests on the tested layer, the cross flow from the adjacent layer has to be accounted for to ascertain reasonable characterization of the tested layer. A new analytical solution for a two-layer system with cross flow behind casing has been employed to understand the effects of cross flow on the transient behavior in the tested layer. Matching of type curves with measured pressures helps diagnose the presence of cross flow behind casing and estimate parameters. The cross-flow rate as a function of time is also estimated by quantifying the hydraulic conductivity of the compromised zonal isolation.
This study shows that the magnitude of the hydraulic conductivity of the compromised zonal isolation or flow channels has a strong effect on the rate of cross flow with the flow capacities of individual layers. There is an upper limit of the conductivity of the zonal isolation beyond which the cross-flow rate is limited by the layer flow capacities. For a given two-layer system, the cross-flow rate increases with time for a constant rate drawdown in the tested layer due to the increasing pressure differential across the compromised zonal isolation. The test duration is another important aspect which lets the cross-flow rate reach a critical value to be detected in the log-log plot of the pressure derivative. This means that a long transient test is likely to be affected substantially by the cross flow behind casing.
Field examples with build-up test data are presented to illustrate the methodology. These show that ignoring the flow behind casing may lead to an over-estimated flow capacity of the tested reservoir layer. Matching of the transient-test data also provides estimates of the conductivity of the zonal isolation, which leads to computing the transient cross-flow rates.
Reconciling Log-Derived Water Saturation and Saturation-Height Function Results through Resistivity Modeling, Core-Log Integration and Image Log Data: A Case Study from Deepwater Gulf of Mexico
Authors: Miranda Javier , Rabinovich Michael , Hamman Jeffry , Mousavi Maryam 
Published: September 2015

Abstract
Saturation Height Functions (SHF) have a key role in reservoir description and in quantifying oil in place. The function(s) must compare well with other sources of water saturation (Sw) when available, such as core measurements and well-log interpretations. We have reconciled the different Sw sources through a reliable SHF function based on the Brooks-Corey model with parameters optimised for Thunder Horse (TH) Field. The function is used to populate oil volumes in the 3-D static and dynamic models.
Thunder Horse is one of the largest deep-water fields in Gulf of Mexico and is operated by BP, with ExxonMobil as a co-owner. TH is divided in two trapping structures: TH North (THN) and TH South (THS). The field has multiple Miocene turbidite reservoirs commonly grouped in units known as the Pink, Brown, and Peach. Thunder Horse is fortunate to have Dean-Stark (D-S) and well-log data sets that detail the Sw changes at and above the oil-water contact (OWC). We developed a continuous log-derived Sw after appropriate model calibration with D-S measurements. Subsequently, we applied the Brooks-Corey SHF model with parameters defined for each rock type in TH area based on an iterative regression to the log-interpreted Sw following a workflow we developed.
This case study illustrates methods and results of reconciling saturations determined from a number of techniques and validation of the outcomes with independent borehole and direct measurements from core. Two cases where differences were observed are addressed by combining resistivity modeling and borehole images with core-log integration.
A comparison of binary vs. continuous net-to-gross (NTG) on Hydrocarbon Pore Volume, based on SHF and log-derived Sw, proved the volume impact is not significant for the highest NTG TH Pink reservoirs. However, the deliverable provides significant value through a consistent and defendable linked saturation and net-to-gross suitable for use in reservoir modelling.
Investigation of Wettability and Fluid Distribution in Organic-rich Mudrocks using NMR Two-Phase Simulation
Authors: Chi Lu , Heidari Zoya , Garcia Artur Posenato 
Published: September 2015

Abstract
Interpretation of NMR relaxometry in organic-rich mudrocks still remains a challenge for petrophysicists. A reliable numerical simulation of NMR response in these rocks helps in better understanding of the NMR relaxometry data and the corresponding petrophysical properties (e.g., the wettability and fluid distribution in the pore space). The hydrocarbon-wetting or mixed-wetting characteristics of organic-rich mudrocks have significant impacts on hydrocarbon recovery from the rocks, but quantification of wettability using conventional well-log interpretation methods remains a conundrum. The objectives of this paper are (a) to introduce a NMR two-phase simulation method to model the NMR responses in organic-rich mudrocks and (b) to investigate the effects of wettability alteration and fluid distribution on NMR relaxometry using numerical simulations.
We simultaneously simulate the NMR responses from both water and hydrocarbon phases in organic-rich mudrocks using a random-walk algorithm. The main input to this two-phase NMR simulator is a digital rock matrix reconstructed from 3D pore-scale images of organic-rich mudrock samples, including water, inorganic grains, hydrocarbon, and kerogen. The pore-scale digital images are obtained from FIB-SEM (Focused Ion Beam Scanning Electron Microscope) images. The output of the NMR simulator is the NMR transverse magnetization decay in the rock matrix. The NMR T2 distribution is estimated by inversion of the simulated magnetization decay using a curvature smoothing method. We also separate the individual T2 distribution peaks from different pores and compare them against the combined T2 distribution to demonstrate the reliability of the simulation results.
We successfully simulated NMR T2 distribution in synthetic and actual organic-rich mudrock samples. We also showed that the alteration of wettability and fluid distribution within the organic-rich mudrock matrix have a measurable impact on NMR T2 distribution. The introduced simulation method enables further developments on interpretation of NMR measurements in organic-rich mudrocks, which has been challenging in laboratory experiments. The outcomes of this paper can improve the understanding of the parameters affecting NMR relaxometry in organic-rich mudrocks. They also potentially enhance the interpretation of NMR borehole measurements for real-time assessment of porosity, pore-size distribution, and wettability.