bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Review of Pulse Fracturing Treatment: An Emerging Stimulation Technique for Unconventional Reservoirs
Authors: Tariq Zeeshan , Mahmoud Mohamed , Abdulraheem Abdulazeez , Al-Nakhli Ayman , Bataweel Mohammed 
Published: March 2019

Abstract
The enormous resources of hydrocarbons hold by unconventional reservoirs across the world along with the growing oil demand make their contributions to be most imperative to the world economy. However, one of the major challenges faced by oil companies to produce from the unconventional reservoirs is to ensure economical production of oil. Unconventional reservoirs need extensive fracturing treatments to produce commercially viable hydrocarbons. One way to produce from these reservoirs is by drilling horizontal well and conduct multistage fracturing to increase stimulated reservoir volume (SRV), but this method of increasing SRV is involved with higher equipment, material, and operating costs.
To overcome operational and technical challenges involved in horizontal wells multistage fracturing, the alternative way to increase SRV is by creating multiple radial fractures by performing pulse fracturing. Pulse fracturing is a relatively new technique, can serve as an alternative to conventional hydraulic fracturing in many cases such as to stimulate naturally fractured reservoirs to connect with pre-existing fractures, to stimulate heavy oil with cold heavy oil production technique, to remove condensate banking nearby wellbore region, and when to avoid formation damage near the vicinity of the wellbore originated due to perforation. Pulse fracturing is not involved with injecting pressurized fluids into the reservoir, so it is also a relatively cheaper technique.
The purpose of this paper is to present a general overview of the pulse fracturing treatment. This paper will give general idea of the different techniques and mechanisms involved in the application of pulse fracturing technique. The focus of this review will be on the comparison of different fracturing techniques implemented normally in the industry. This study also covers the models developed and applied to the simulation of complex fractures originated due to pulse fracturing.
Development of A New Chemical Treatment for Removing Water Blockage in Tight Reservoirs
Authors: Hassan Amjed , Mahmoud Mohamed , Al-Majed Abdulaziz , Alade Olalekan , Al-Nakhli Ayman , BaTaweel Mohammed , Elktatany Salaheldin 
Published: March 2019

Abstract
In petroleum industry, great challenges are associated with producing hydrocarbon from unconventional reservoirs. Tight reservoirs are characterized with low permeability which reduces the hydrocarbon flow into the wellbore. Water blockage is considered as a potential damage issue in tight reservoirs due to increasing the water saturation around wellbore region and eventually decreasing the relative permeability of hydrocarbons. Acid fracturing or hydraulic fracturing are required to remove the damage and enhance the formation conductivity. The objective of this paper is to propose a new technique to remove the water blockage from tight formations using thermochemical treatment. Chemicals that generate pressure and heat at reservoir conditions are used to remove the water bank from tight core samples.
Coreflooding experiments, capillary pressure and NMR measurements were conducted as well as routine core analysis. The impact of thermochemical treatment on improving the formation productivity was quantified. The effect of thermochemical injection on rock integrity was analyzed by evaluating the pore geometry before and after the chemical treatment. Thermochemical treatment resulted in a significant improvement in the core conductivity. NMR indicated that, tiny fractures were created in the core samples due the thermochemical flooding. Capillary pressure measurements showed that, the capillary pressure was reduced by 55.6% after the chemical treatment.
The results of this study highlight that water blockage is great challenge in tight gas reservoirs. Injecting thermochemical fluids into tight samples reduces the capillary forces significantly, which leads to remove the water accumulation. Therefore, considerable enhancement was observed in the rock conductivity. This study provides a novel approach for removing the water blockage from tight formations using environmentally friendly chemicals. Chemicals that generate heat and pressure at downhole conditions were used to create tiny fractures. This treatment was able to remove the water blockage from tight sandstone cores and improve the productivity index by reducing the capillary forces.
The Role of Transient Perturbations and Heterogeneities in Subsurface Wave Propagation - A Scalable Numerical Solution
Authors: San-Roman-Alerigi Damian 
Published: March 2019

Abstract
The objective of this work is to present the development of a numerical model for wave propagation in materials with time-varying, heterogeneous, and non-linear properties. Materials change with time as the result of complex linear and non-linear processes, which can occur due to natural causes or induced. Wave phenomena in this context brings about an interesting and complex problem, which involves the solution to coupled equations which describe interlinked multiphysics phenomena. Thus, understanding the dynamics of this interaction is beneficial to numerous applications across different industries and applied research; e.g. acoustic characterization of moving fluids, laser-fluid interaction, distributed optical fiber sensing, photonic integrated systems, among others. Numerical models, therefore, are indispensable to gain a deeper insight about the physical dynamics of the process and, ultimately, purvey a platform to design and test new applications and technologies.
Over time some numerical models have been proposed to simulate wave phenomena in these situations. The method and solution reviewed in this work provides a unique solution to develop and optimize multiple applications. For example, it can be used to model the interaction of electromagnetic waves with travelling Bragg mirrors produced by temperature or pressure changes in optical fibers, which is the basis of fiber-based distributed fiber sensing; the scattering of acoustic waves by transient disturbances in fluid flow that may arise from gas bubbles or variations in the density of fluids; and the propagation of an electromagnetic pulse in a rapidly moving and varying fluid.
The mathematical description of the process was derived originally for electromagnetics; yet, the numerical solver and mathematical treatment is generic and can be applied to other wave phenomena. The derivation departs from physical principles to write a generalized set of equations that describe wave propagation in time-varying, heterogeneous, and non-linear materials. The resulting set of hyperbolic partial differential equations (PDE) includes diffusive and convective terms that fully describe the wave interaction and process. Linear and nonlinear spatial and time heterogeneities in the material are assimilated into the convective terms of the hyperbolic wave equation. The solver was implemented using a semi-discrete and multidimensional scheme based in the finite-volume method which is highly scalable. Extension to other wave phenomena is discussed by analyzing the parameter correspondence for the acoustic and electromagnetic case.
Sabriyah Lower Burgan Field EOR Development Study: Use of Sacrificial Wells to Minimize Water Encroachment
Authors: Al-Murayri Mohammed Taha , Al-Mayyan Haya Ebrahim , Al-Ghnemi Mohammad Faleh , Pitts Malcolm , Dean Elio , Wyatt Kon , French Josh , Skeans Elii 
Published: March 2019

Abstract
Sabriyah Lower Burgan (SALB) is a multi-billion-barrel reservoir located in north Kuwait with favorable fluid and rock properties, and a strong active aquifer. The presence of the aquifer is advantageous for primary development of the reservoir but presents a challenge for conventional application of chemical EOR (CEOR). SALB has passed multiple stages of a CEOR evaluation process (technical screening, laboratory formulation design, SWCT, pilot design, risk assessment, etc.), and is currently considered for a multi-well CEOR pilot. This study investigates the viability of using sacrificial wells in the management of the lateral aquifer present in the SALB Layered formation, which represents a sought after CEOR target. The objective of these sacrificial wells is to reduce the potential negative impacts of the existing aquifer on commercial CEOR deployment.
The adopted approach involved using a history matched field model with EOR parameters calibrated to laboratory results for ASP and CO2 technologies. The multi-well field model was used to evaluate and compare different development scenarios to assess the impact of sacrificial wells. These scenarios were evaluated based on production performance and economics.
It was observed that strong aquifer presence complicates both CO2 and ASP project implementation. Challenges due to the aquifer include loss of EOR agents into the water leg, difficulty in accounting for effective pore volume of the project and water encroachment. It is difficult for EOR project economics to compete with an effective aquifer primary development. Sacrificial wells can be used to reduce the strength of the aquifer, potentially improving the effectiveness of the EOR technology. Although the sacrificial wells are unlikely to be economic on their own, they can improve the overall economics of the project. The amount of recovered oil due to EOR deployment is an important parameter to evaluate the economic feasibility of using sacrificial wells.
Many reservoirs around the world have strong aquifers, for which conventional reservoir engineering advice has been to avoid EOR application. This paper introduces a novel approach to deal with these strong aquifers by strategically placing wells that can reduce the aquifer's strength, thus making EOR deployment more favorable.
Comparative Study of the Mechanical Properties of Reduced Density Cements
Authors: Deshpande Abhimanyu , Jones Paul , Jadhav Rahul , Pangu Ganesh , Mishra Vaishali 
Published: March 2019

Abstract
Cementing a casing string across weak formations or depleted reservoirs has the added challenge of tailoring the cement slurry to meet delivery criteria (i.e., density and rheology) while maintaining the mechanical properties of the set cement necessary to provide a dependable barrier. To help prevent fracturing the formation and inducing losses, cement density is often reduced, which strongly influences the mechanical properties of set cement. Common strategies for reducing cement density consist of adding water in the cement slurry; using additives such as hollow glass microspheres (HGS), synthetic latex, and elastomers; using foam cement; or adding resin. This paper discusses how cement slurries with reduced densities are designed using both traditional and alternative methods of making cement/resin composites and provides insight into the advantages and drawbacks of each.
Stable cement slurries with a density of 13 lbm/gal were designed, and placement characteristics of thickening time and rheology were evaluated for the liquid cement slurry. Unconfined compressive strength (CS), Young's modulus (YM), tensile strength, permeability, and shear bond were investigated on the cured samples. Before taking mechanical and permeability measurements, slurry stability was verified using sedimentation testing. Any slurry that did not exhibit the necessary stability was redesigned and tested again. Only the final slurry designs exhibiting stability are discussed in this paper.
Cement-resin composite cements exhibited similar performance to those containing HGS in terms of CS, YM, tensile strength, and shear bond but exhibited greater than two times the CS when compared to the synthetic latex modified, water-extended, and elastomeric slurry designs. The cement-resin composite provided almost twice the shear bond strength and increased tensile strength by 50% compared to other slurry compositions.
In the current work, cement-resin composite, synthetic latex modified, microbead-based, water-extended, and elastomer-modified slurries are compared at 13 lbm/gal. Various parameters, such as mixability, ease of placement in the annulus, strength development, and long-term cement integrity, are evaluated. Traditional and newly introduced techniques for reducing cement slurry density and the resultant mechanical properties of the set solids are investigated. This information provides an alternate method of using cement-resin composites for designing and delivering dependable barriers tailored for low density applications.
Effective Geomechanic Approach for Wellbore Stability Analysis
Authors: Alsiyabi Kuthar , AL-Aamri Mohammed , Siddiqui Numair Ahmed 
Published: March 2019

Abstract
The success of drilling operations strongly depends on proper mud weight design. In fact, unsuccessfully optimizing the mud weight could lead to wellbore collapse. Within the oil industry, Mogi and Mohr-Coulomb models are the most-practiced failure criterion used in predicting critical mud weight.
This paper was aimed at inspecting these models regarding mud weight prediction. A new comparison concept was also developed. Furthermore, the different stochastic perspectives were carried out in the study. Based on field data, the required mud weight was found using the Mogi and Mohr-Coulomb failure criteria. The results suggested that the predicted pressure from the Mogi model is considerably close to the real mud weight. The study is also developed using the new pragmatic comparison criteria called the breakout width.
The predicted mud weight from both models was separately utilized to obtain the width of shear failure (breakout) by applying the simple analytical model. The results revealed the breakout dimension was a bit over-predicted with respect to the Mohr criteria. Moreover, the optimum mud weight was a function of input parameters, which include stresses and rock properties.
The knowledge of such parameters depends effectively on the quality of the parameters. The deterministic approach was presented to display the influence of each parameter by developing tornado diagrams. The analysis was defined that the maximum horizontal stress is the most influential parameter for collapse pressure prediction for both models. In addition, overburden stress has a considerable effect on the Mogi model and was ignored in the Mohr criteria. Other parameters were also captured in the analysis. In this paper, the probabilistic analysis approach using Monte Carlo simulation was also implemented into wellbore stability models to cover all the significant parameters with their uncertainties rather than certain values for improving predictions. Based on the analysis, the mud weight optimization will have a direct impact on future drilling practices and operation costs.
Detailed Comparison of Processed Sand vs. Unprocessed Sand vs. High-Strength Proppant for Fracturing Applications
Authors: Shakeel Muzzammil , Abdulrazzaq Waseem , Abdullatif Osman , Benaafi Mohammed 
Published: March 2019

Abstract
A detailed study comparing various properties and attributes of local Saudi Arabian sand (processed and unprocessed) and high-strength proppant (HSP) for hydraulic fracturing applications is discussed. Further, quartz grain crystallinity, texture, quality, and mechanical durability (strength) are described and an insight into the prospects of sand application viability during hydraulic fracturing is provided.
An in-depth comparison of processed sand, unprocessed sand, and readily available HSP widely used in the industry was performed. It is well known that the Middle East region, particularly Saudi Arabia, has an abundance of sandstone formations ranging from the Cambrian to Quaternary age; outcrops of these formations extend from northern to southern parts of Saudi. These formations have varying grain sizes and other physical attributes that must be studied to grade their possible performance as hydraulic fracturing proppants. Unprocessed sand samples were collected from various central and southern Saudi sandstone formations. Petrographic analysis, including thin section and scanning electronic microscopy (SEM), was conducted on sand samples to quantify the percentage of polycrystalline quartz grains and define their surface features. Crush-resistance testing was performed on the samples to compare the mechanical durability of the sands and HSP.
The results of this study confirmed that polycrystalline quartz grains are more abundant in coarse-grained sandstones than those fine-grained. Mechanical durability decreased with an increased percentage of polycrystalline quartz grains, strained grains (with undulose extinction), and surface features. The metamorphic nature of the quartz grain source rock and intense chemical weathering along the quartz grain surface reduce its strength. HSP demonstrates greater mechanical durability compared to processed and unprocessed sand, keeping in mind, the processed sand was from a specific sandstone formation.
The suitability of Saudi sandstones for the petroleum industry's use is dependent on the mechanical durability of quartz grains, which, in turn, depends on the source and chemical weathering of those grains. Comparatively, HSP is more durable and mechanically strong; however, processed sand has an edge over unprocessed sand.
Reframing Exploration Workflows for Small to Super-Merge 3D Seismic Interpretation
Authors: Taylor David , Ali Sadaqat 
Published: March 2019

Abstract
Techniques for 3D seismic interpretation by geoscientists are continuously undergoing improvements, and future exploration is anticipated to continue to benefit from high-confidence first pass interpretations utilizing all of the available seismic and well data. Workflows have been developed on a ‘super-merge’ 3D volume to produce attribute-enhanced chronostratigraphic stratal surfaces, allowing interpretation of regional-scale seismic facies and associated seismic geomorphology and tectonostratigraphy.
In this example, a semi-supervised machine-based learning workflow has provided rapid turnaround interpretation of the structural framework and chronostratigraphy throughout the entire 3D seismic volume, maximizing the value of the seismic information. This workflow consists of a three-step auto-tracking workflow to build a Relative Geological Time (RGT) geo-model directly from the seismic volume. This enables more time to spend on geological validation and interpretation of the stratal surface seismic geomorphology. Study results have provided the foundation for rapid turnaround well and seismic integrated play fairway maps; a powerful tool for stimulating exploration in mature areas or wildcat acreage assessment.
This study focused on Middle and Upper Jurassic carbonates deposited on a broad low angle platform on the Arabian Plate. Interpreting in map view on RGT constrained stratal surfaces with attributes such as, relative acoustic impedance and spectral decomposition, is invaluable for visualization since the stratal surface follows the morphology of the imaged geologic features. The ability to select any stratal surface within the volume and flatten, either on a seismic display or the Relative Geological Time geo-model, is particularly useful to establish the timing of major tectonic episodes and accommodation space fluctuations.
ASP Flood Application for a High-Temperature, High-Salinity Carbonate Reservoir
Authors: Abalkhail Nassir A. , Liyanage Pathma J. , Upamali Karsinghe A. , Pope Gary A. , Mohanty Kishore K. 
Published: March 2019

Abstract
The goal of this work was to develop a highly efficient alkaline-surfactant-polymer (ASP) process applicable to a high temperature (~100 °C), high salinity (~60,000 ppm) giant carbonate reservoir with very low surfactant retention, an essential requirement for low chemical cost. Phase behavior tests were conducted with anionic surfactants, alkali, co-solvents, brine, and crude oil to identify chemical formulations with ultra-low IFT under reservoir conditions. Corefloods were first conducted in outcrop carbonate cores and then in reservoir cores. The effluent was analyzed for oil, surfactant, pH, salinity and viscosity. Pressure drop was monitored across 4 sections of the core to monitor front propagation. Surfactant adsorption on carbonate surfaces decreases at high pH. The conventional alkali used for ASP floods of sandstones is sodium carbonate. However, sodium carbonate cannot be used in formations containing anhydrite, which is the case for the target reservoir. For this reason, ammonia, sodium hydroxide and a new organic alkali were studied for this application. Ultralow IFT (~0.001 dynes/cm) was achieved with several ASP formulations using the reservoir oil. Coreflood experiments using both outcrop limestone and carbonate reservoir core were conducted using these alkalis. The coreflood results showed good oil recovery and low surfactant retention.
A Closer Look on Viscosity and Divergence Effects of Gel Treatments in Fractured Systems
Authors: Alshehri Amar J. , Wang Jinxun , Kwak Hyung T. , AlSofi Abdulkarim M. 
Published: March 2019

Abstract
Polymer gel treatment is a successful technology for conformance improvement. Achieving effective deep conformance control in high-temperature reservoirs requires improving the performance of gel in these environments and a deep understanding of gel-conformance control mechanisms inside reservoir rocks.
In this work, a laboratory study was conducted to evaluate a polyacrylamide/chromium gel system for a carbonate reservoir at high-temperature and high-salinity (HTHS) conditions. Displacement experiments combined with nuclear magnetic resonance (NMR) measurements were performed to investigate the mechanisms of conformance treatment as well as demonstrate the potential of oil production improvement by a gelling system. Coreflooding tests were performed on carbonate core samples with different configurations of high-permeability channels. Both gel treatment and polymer flooding experiments were conducted to quantify and differentiate between fluid-diversion and viscous effects on oil production improvement due to the treatment. Detailed spatial fluid variations inside the core samples before and after gel treatment were closely monitored using low-field NMR techniques.
Both coreflooding experiments and NMR measurements clearly showed that significant oil production improvement was achieved by gel treatment. The bypassed oil during waterflooding was effectively mobilized. Gel treatment is more efficient in oil production improvement for more heterogeneous core samples. The comparison study of gel treatment and polymer flooding helps gain insight into the mechanisms of oil displacement.
Results show that the blockage or fluid-diversion effect plays a more significant role in oil production improvement after gel treatment. The viscous effect of gelant flow helps mobilize oil in the matrix region. The oil production improvement by gel treatment is mainly attributed to the fluid-diversion effect, especially for the treatment in high-permeable configuration. Moreover, results of the study demonstrate the potential of the studied gel system for carbonate reservoirs at high temperature. NMR techniques add additional valuable information to conventional displacement tests to identify the dominant mechanisms of oil mobilization.