bluuebunny/crossref_metadata_2025_split huggingface dataset:
NMR Investigation of Viscoelastic Surfactants Compatibility with Corrosion Inhibitors
Authors: Afra Salar , Samouei Hamidreza , Nasr-El-Din Hisham 
Published: January 2020

Viscoelastic surfactants (VES) have been successfully applied as acid-diversion fluids. However, high temperature, interaction of VES and metallic cations, alcohol-based additives, and chelating agents all interfere with the apparent viscosity of the VES-based acid and reduce its efficiency. One of the most essential additives in acidizing that can significantly interfere with VES behavior is corrosion inhibitors. Many parameters would impact the performance of corrosion inhibitors including tabular materials, acid types and concentrations, as well as the presence of other additives that might interfere with the corrosion inhibitors. Hence a wide range of corrosion inhibitors is available to address corrosion issues adequately. The present study characterizes the interactions of various types of industrial corrosion inhibitors with different kinds of VES-based systems including zwitterionic and nonionic surfactants.
Viscosity measurements were conducted on the VES-based solutions combined with different concentrations of tested corrosion inhibitor formulae, the industrial packages, to characterize the rheological properties of the VES-based acids. To understand the nature of the VES interactions with corrosion inhibitors, nuclear magnetic resonance (NMR) spectroscopy was conducted.
The results of rheological measurements showed that addition of different types of corrosion inhibitors in the industrial concentration range leads to change in the conformation of micellar structures and rheology of the VES-based solutions. NMR was conducted to determine the chemical groups involved in the interaction/reaction of corrosion inhibitors and viscoelastic surfactants. Furthermore, the effects of additives and solvents present in industrial corrosion inhibitors were studied. The results showed that amide part of VES is the leading functional group that can interact with corrosion inhibitor solutions and causes alternation of micellar structures due to change in the repulsion forces between surfactants headgroups.
The results presented in this study can be used to select corrosion inhibitors more efficiently and optimizing their effectiveness in the presence of VES-based fluids. These results can be utilized to predict any probable interactions and rheological changes in VES-based stimulation fluids due to the addition of corrosion inhibitors.
A Numerical Model to Assist with the Selection of Non-Metallic Piping Materials for Offshore Developments
Authors: Alsaddah Abdullah , Almedallah Mohammed K. , Clark Stuart R. , Walsh Stuart D. C. 
Published: January 2020

The oil and gas industry is moving towards the use of non-metallic pipeline material, such as reinforced thermoplastic and flexible piping, for applications in offshore fields. However, these materials have certain pressure and diameter constraints that require careful analysis prior to deciding on the appropriate piping material to be installed. The objective of this paper is to suggest an integrated approach that considers the reservoir properties, well path and the field pipeline network to determine the operating pressure and diameter that is ultimately used to select the appropriate pipeline material for offshore field developments.
The proposed integrated model uses a series of three optimization techniques to determine the optimum field development architecture, which includes the allocation of wells, pipeline network configuration and well path optimization. The model starts by applying a continuous optimization technique to find the optimum subsurface and surface network. It then uses a graph-theorical approach to find the optimum pipeline route based on an appropriate minimum radius of curvature while considering the presence of obstacles in the seabed. From the results of this optimization, a dynamic nodal analysis is applied to determine the optimum operating conditions of the field (e.g. pressure and well rate). Finally, mixed-integer linear programming (MILP) is used to optimize the pipeline diameter subject to constraints based on the maximum pressure and pipeline size of different non-metallic pipeline materials.
Analysis of the model results demonstrates that ignoring any of the reservoir, wellbore and surface facility components results in an underestimation or overestimation of the operating conditions of the field, which subsequently leads to incorrect selection of pipeline materials. Therefore, an integrated approach is necessary to evaluate the non-metallic piping applications in the oil and gas industry.
Fracturing in Coalbed Methane Formations in Ordos Basin: Observations, Simulation, and Improvement Plan
Authors: Han Jun , Liu Chuanqing , Wu Jianjun , Liu Yuan , Niu Li , Wang Weikan 
Published: January 2020

Many operators are developing coalbed methane (CBM) reservoirs from Ordos basin on a regular basis, and fracturing is one of the key measures to increase production from this unconventional resource. Despite the long history and large volume for CBM fracturing stages in the past, the performance from the CBM reservoir is still often inconsistent and differs from expectations. It is necessary to have better understanding of the hydraulic fracturing dynamics in CBM to improve reservoir performance.
CBM reservoirs are well known to be different compared to the conventional formations, and so fracturing involves different considerations. Three key components are integrated in this study to better understand CBM fracturing. Fracturing data from multiple wells are integrated into one database to exhibit a certain pattern of where the better production would be. With the observation from previous microseismic and offset well response, it is confirmed that the fracture geometry has reached to certain length. Based on this observation and analysis, simulation for pressure match is completed to illustrate the hydraulic fracturing geometry and propped fracturing geometry, which leads to an improvement plan for future work.
The improvement plan for the fracturing in CBM is built upon the observation and analysis above. Unlike fracturing in conventional resources, onsite pressure observation and adjustment guidelines are suggested to achieve a better fracturing geometry in CBM because these have been shown to provide higher production over longer period of time.
Using Multicomponent 3D Seismic Data to Define Current Fluid Contacts in Stacked Limestone Reservoirs of a Partially-Depleted Oil Field
Authors: Al-Enazi Falah , Beck Byron 
Published: January 2020

This paper describes the interpretation of compressional and shear wave seismic data, recorded in a multicomponent ocean-bottom cable seismic survey in the Arabian Gulf, to define individual present-day fluid contacts in stacked limestone reservoirs in a partially-depleted oil field.
KJO recorded a multicomponent 3D-4C seismic survey over a dormant, partially-depleted oil field using ocean-bottom cable technology in 2012. Processing of the P-wave, shear-wave and reservoir characterization volumes provided unprecedented resolution of the reservoir architecture, rock and fracture properties, and reservoir fluid distribution to assist in the field redevelopment plan. The reservoir characterization results provided a variety of porosity, fluid & lithology indicators. Vp/Vs ratio was identified as the most reliable fluid indicator. This is expected to be low above the oil-water contact (OWC) and high below the contact.
The field produced oil for many years from five limestone reservoirs. After a multi-year shut-in period, engineering assessment of fluid contacts concluded that the four upper limestone reservoirs, of late-to-middle Cretaceous age, are in vertical communication but also compartmentalized by faulting. Similarly the lower limestone reservoir (early Cretaceous) is also compartmentalized by faulting. Structural interpretation of the new data provided detailed depth maps of each reservoir top together with an updated pattern of axial and wrench faults. Reservoir characterization processing of the new multicomponent seismic data delivered a number of potential fluid indicator seismic attributes: Poisson's Ratio, Vp/Vs ratio and AVO gradient. After evaluation of 16 different seismic volumes, the Absolute Vp/Vs ratio from the PPPS Joint Inversion was selected as the most robust fluid indicator. Structure maps, overlain with the Vp/Vs ratio seismic attribute, showed amplitude shut-offs consistent with structural contours, varying from fault block to block. These maps were used to define present-day fluid distribution for each reservoir level. The results confirmed a) the presence of remaining hydrocarbons in most of the late Cretaceous reservoir compartments; b) middle Cretaceous limestones are largely depleted except for isolated attic volumes, and c) limited depletion in the early Cretaceous reservoir.
This was the first multicomponent reservoir characterization project carried out by KJO. The Vp/Vs ratio results confirmed the fluid distribution as determined by the engineering assessment; identified the sealing faults responsible for compartmentalization of the field, and supported the engineering assessment conclusion that the shallow reservoirs are in vertical communication.
A New Technique to Quantify the Productivity of Complex Wells Using Artificial Intelligence Tools
Authors: Hassan Amjed , Mahmoud Mohamed , Al-Majed Abdulaziz , Abdulraheem Abdulazeez 
Published: January 2020

Nonconventional wells (NCWs) are applied to increase the well deliverability and access the difficult formations. The nonconventional wells have been used to refer for the advanced wells such as highly deviated, horizontal, fishbones or multilateral wells. These wells offer a great potential to maximize the hydrocarbon recovery, however, it is difficult to predict their performance. In the literature, numerous mathematical models were developed to predict the well-productivity. However, the available models have been developed by employing one or more simplifying assumption(s), which may lead to over or under estimate the hydrocarbon production. This paper presents an effective technique to estimate the productivity for nonconventional wells.
In this work, artificial intelligence (AI) technique was utilized to determine the well-productivity for wide range of conditions. The developed models can determine the well performance without introducing the complexity associated with the numerical approaches. Artificial neural network was utilized to estimate the hydrocarbon production for two types of nonconventional wells; fishbone multilateral and hydraulically fractured horizontal wells. Reliable models are presented to quantify the performance of nonconventional wells producing from heterogeneous and anisotropic formations. The developed models evaluate the importance of reservoir properties and well configuration on the well deliverability. Total of 850 data sets were utilized to construct the intelligence models and to validate the prediction performance. Moreover, mathematical equations were extracted utilizing the optimized ANN models. The extracted correlations showed acceptable prediction errors, the absolute error around 7.4% in average.
The novelty of this work is that effective models are proposed to quantify the productivity of nonconventional wells. The proposed models can be utilized to refine commercial software to narrow down the deviations between the actual measurements and simulation outputs. Also, this work can contribute to enhance our understanding of the oil-field management by improving the prediction of well deliverability. Consequently, this study can help in optimizing the well planning for complex wells such as hydraulically fractured horizontal and fishbone multilateral wells.
Wellbore Far-Field Imaging for High Resolution Reservoir Characterization
Authors: Denis P. Schmitt , Thierry-Laurent D. Tonellot 
Published: January 2020

Depth images produced using sonic waveform data have the recognized potential to provide deep-look data applied to reservoir and fracture characterization. However, their usage is relatively sparse.
The geo-bodies that can be imaged with sonic logs do not need to intersect the wellbore and can be a fault, a fracture, a lithological boundary or a fluid contact, for example. The literature on near-wellbore imaging has been split in two camps for quite a while: P-wave versus S-wave imaging; the latter receiving lots of attention recently. In fact, one does not preclude the other.
The approach used in this work enables the nearly routine processing of all acquired acoustic data, irrespective of the wireline acoustic tool used, as well as the source (monopole or dipole), increasing the possibility of unveiling unsuspected and/or useful information from the reservoirs. We present several examples of images obtained from carbonate reservoirs in horizontal and slanted wells, including for runs of more than3000 feet. The imaging is performed using a proprietary reverse time migration implemented to run in parallel. In several instances, the image reached 200 feet from the wellbore and boundaries within a reservoir are delineated over several hundred/thousand feet within the formation at a distance from the wellbore varying from 180 feet to a few feet. An example shows the repeatability of the process and how structural images can be obtained at a sub-seismic scale. Besides being constrained by the formation properties, the distance reached during imaging is a function of the listening time. Pre-processing, such as the removal of the borehole modes is a critical step for detailed structural imaging. Its design can affect the final image, as illustrated in this paper.
As this technology becomes more mature, logging-based structural imaging away from the wellbore can be the missing scale between borehole wall images and borehole seismic such as VSP, enabling the estimation of more complete/detailed geological models helping the interpretation and the design of future well paths.
Improved Well-Control Management Through Progressive Optimization with Generalized Barycentric Coordinates and Manifold Mapping
Authors: Ciaurri David Echeverría , Beltrán Gustavo A. Moreno , Navarro Jhonatan Camacho , Mejía Jorge A. Prada 
Published: January 2020

Well-control management is nowadays frequently approached by means of mathematical optimization. However, in many practical situations the optimization algorithms used are still computationally expensive. In this paper we present Progressive Optimization (PO), a simulator-nonintrusive four-stage methodology to accelerate optimal search substantially in well-control applications.
The first stage of PO consists in a global exploration of the search space using design of experiments. Thereafter, in the second stage, a fast-to-evaluate proxy model is constructed with the points considered in the experimental design. This proxy is based on Generalized Barycentric Coordinates (GBCs), a generalization of the concept of barycentric coordinates used within a triangle. GBCs can be especially suited to problems where nonlinearities are not strong, as is the case often for well-control optimization. This fact is supported by the good performance in this type of optimization problems of techniques that rely strongly on linearity assumptions, such as Trajectory Piecewise Linearization, a procedure that is not always applicable due to its simulator-intrusive nature. In the third stage, the precision of the proxy model is iteratively improved and the enhanced surrogate model is re-optimized via Manifold Mapping (MM), a method that combines models with different levels of accuracy. MM has solid theoretical foundations and leads to efficient optimization schemes in multiple engineering disciplines. The final and fourth stage aims at additional improvement resorting to direct optimization of the best solution from the previous stages. Nonlinear (operational) constraints are handled in PO with the filter method. The optimal search may be finalized earlier than at the fourth stage whenever the solution obtained is of satisfactory quality.
PO is tested on two waterflooding problems built upon a synthetic model previously studied in well-control optimization literature. In these problems, which have 120 and 40 well controls and include nonlinear constraints, we observe for PO reductions in computational cost (for solutions of comparable quality) of around 30% and 50% with respect to Hooke-Jeeves Direct Search (HJDS), which, in turn, outperforms Particle Swarm Optimization (PSO). HJDS and PSO are simulator-nonintrusive algorithms that usually perform well in optimization for oil-field operations.
The novel concepts of Generalized Barycentric Coordinates and Manifold Mapping within the framework of the Progressive Optimization paradigm can be extremely helpful for practitioners to efficiently deal with optimized well-control management. Savings of 50% in computing cost may be translated in practice into days of computations for just a single field and optimization run.
Enhancing Oilfield Water Injection Distribution and Energy Efficiency through Surface Network Optimizations
Authors: White Ramsey , Fischbuch Darryl , Bahattab Mohammad 
Published: January 2020

Objectives/Scope: A Saudi Aramco facility is forecasted to process crude from an adjacent oil field. Additionally, the forecasted produced water rates and injection pressure are anticipated to increase. This requires pump upgrades thatincrease power consumption. Moreover, the produced water, normally reinjected into the reservoir, needs to be redistributed through upgraded headers to align with the overall reservoir management strategy. A hydraulic assessment was conducted to determine the ideal balance through optimization of capital expenditures and forecasted operating expenses.
Methods, Procedures, Process: The study was conducted using a hydraulic model of the pipeline network and produced water pumping system. Several scenarios of pump stages and disposal header configurations were simulated. Pump discharge pressure can be manipulated by increasing the number of stages. Alternatively, the existing disposal water injection network can be upgraded by replacing with larger lines, looping and or rerouting of injection headers. Based on the scope of each upgrade, capital costs and forecasted operating expenditures were quantified.
Results, Observations, Conclusions: Technical solutions through a hydraulic assessment was developed to achieve the ideal balance through optimization of capital expenditures and operating expenses. A 15% reduction in forecasted energy consumption was achieved by reducing the required discharge pressure from the salt water injection pumps. A major capital cost avoidance was also accomplished because of the proposed modification. Moreover, additional operational flexibility is provided, allowing for the facility to inject into other flanks as required, to reduce injection header pressure and fulfill reservoir management strategy. Further optimization will be explored in the future, as water injection redistribution to other flanks are introduced.
Novel/Additive Information: This study was conducted using detailed hydraulic assessmenttools that were used to determine the optimum facility designrequired to achieve the overall water injection strategy for the field. It includes hydralic modeling with Geographic Information System(GIS) capabilities, which considers the impact of the elevation profile on the hydraulics.
Applying Lean Methodology to Improve the Operational Efficiency of a Well Stimulation Vessel
Authors: Gondalia Ravi Ramniklal , Narayan Shashank , Sharma Sigra , Diwakar Harish , Patil Ravindra Madav , Palli Venkata Ramanamurthy 
Published: January 2020

Western offshore fields in the South and East Asia region are depleted and require frequent stimulation. To efficiently deliver stimulation treatments, a supply vessel has been converted into a well stimulation vessel with limited well flowback capability. This is one of only a few vessels in the world that has a zero-discharge flowback facility with certification by industry-recognized external organizations. Developing the vessel and operations plans required a systematic approach to continuous improvement.
The process involved identifying the criteria for efficiency and effectiveness for an offshore stimulation vessel and building in continuous improvement methodology with a focus on visual order, organization, safety, and standardization of operations. A lean management methodology was applied to systematically analyze and improve operational process efficiency in relation to organization, orderliness, cleanliness, adherence, and self-discipline. A series of checklists were introduced to enable procedural adherence with monthly self-evaluations to identify areas of improvement and develop remedial work plans.
This paper describes the vessel conversion and installation process as well as the lean approach and health, safety, and the environment (HSE) requirements. The vessel has been used for a variety of stimulation jobs such as proppant fracturing, sand control pumping, matrix stimulation, nitrogen pumping, and limited flowback. These stimulation jobs have been achieved with no recordable injuries and zero nonproductive time by introducing operating procedures, training crew members in those procedures, and monitoring adherence. Systematic efficiency improvements related to materials and procedures led to a 23% reduction in onboard crew size, thereby reducing the risk exposure to personnel. Vessel repair and refabricating expenditures have been reduced by 53%. This vessel has delivered an average of 40 jobs per month, achieving a peak job frequency of 64 jobs per month and treating more than 1,000 wells to date.
This paper provides an overview of the practices developed and lessons learned for operating an offshore stimulation vessel, including process flow charts with trackers and checklists designed to improve operational efficiency.