bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating Diffusion Coefficients of Shale Oil, Gas, and Condensate with Nano-Confinement Effect
Authors: Du Fengshuang , Nojabaei Bahareh 
Published: October 2019

Abstract
Molecular diffusion plays an important role in oil and gas migration and transport in tight shale formations. However, there are insufficient reference data in the literature to specify the diffusion coefficients within a porous media. This study aims at calculating diffusion coefficients of shale gas, shale condensate, and shale oil at reservoir conditions with CO2 injection for EOR/EGR. The large nano-confinement effects including large gas-oil capillary pressure and critical property shifts on diffusion coefficient are examined. An effective diffusion coefficient that describes the diffusion behavior in a tight porous solid is estimated by using tortuosity-porosity relations as well as the measured shale tortuosity from 3D imaging techniques. The results indicated that nano - confinement could affect the diffusion behavior through altering the phase properties, such as phase compositions and densities. Compared to bulk phase diffusivity, the effective diffusion coefficient in a porous shale rock is reduce by 102 to 104 times as porosity decreases from 0.1 to 0.03.
Use of a New Well Productivity Model and Post-Frac Rate-Transient Data Analysis to Evlauate Production Potential of Refracturing Horizontal Wells in Shale Oil Reservoirs
Authors: Yang Xu , Guo Boyun , Zhang Xiaohui 
Published: October 2019

Abstract
Production data and analytical models derived from coupling the linear flow in the reservoir and the linear flow in hydraulic fractures were used in this study to optimize fracture spacing for maximizing productivity of shale oil and gas wells through refracturing. This study concludes that productivity of multi-fractured horizontal wells is inversely proportional to the fracture spacing. The shortest possible fracture spacing should be used to maximize well productivity through refracturing. This supports the practice of massive volume fracturing where as many as perforation clusters with the shortest possible spacing are used for pumping massive proppant into the created hydraulic fractures. Production data analysis indicates that the multi-fractured horizontal oil and gas wells could have higher productivity if they were fractured with less perforation cluster spacing. Mathematical model analysis implies that reducing the cluster spacing from 70 ft to 15 ft through refracturing can doubled well productivity, with the Minimum Required Cluster Spacing (MRCS) determined by well completion constraints (packers, perforation clusters, and casing couplings). Result can be checked for fracture trend interference on the basis of analyses of pressure transient data or production data.
New Friction Reducer Boosters Enhance Friction Reduction and Proppant Transport: Case Studies - Superlaterals
Authors: Xu Liang , Ogle James , Collier Todd , Straffin Ian , Dubois Teddy , Nichols Rome , Uka Oeklers Delvina 
Published: October 2019

Abstract
Friction reducer (FR) performance has been enhanced by adding a FR booster in both fresh water and up to 100% high total dissolved solids (TDS) produced water during hydraulic fracturing applications. However, it is not well understood how the boosters actually increase FR performance during pumping and the effects they have on surface treating pressure and proppant transport. Both laboratory results and field studies of FR and boosters are discussed. Additionally, it was observed that tailored booster chemistry appears to increase FR viscosity significantly, thereby helping ensure better proppant transport during fracturing.
Flow loop and viscosity tests were conducted to demonstrate the benefits of using a booster and the results were analyzed to understand the potential mechanisms that dictate the observed phenomena. Laboratory results suggest that the FR booster enables rapid hydration and inversion of FRs, which typically results in decreased treating pressure to approximately 800 psi compared to FRs without boosters. This pressure decrease during pumping for a single fracture stage has been frequently observed in several shale plays, such as the Wolfcamp, the STACK/SCOOP, and the Marcellus/Utica. A lower FR concentration can be used to transport proppant because the booster helps reach the same or higher viscosity. Case studies are discussed to further understand the synergy between FRs and boosters.
Artificial Intelligence Assisted Hydraulic Fracturing Design in Shale Gas Reservoir
Authors: He Qin , Zhong Zhi , Alabboodi Maher , Wang Guochang 
Published: October 2019

Abstract
Hydraulic fracturing is a typical and vital technique applied in shale gas reservoir development. Numerical simulation used to be a common tool to optimize the parameters in hydraulic fracturing design determining the stage numbers, injection pressure, proppant amount, etc. However, the current understanding of shale gas storage and transport mechanism (e.g. adsorption/desorption, diffusion) is basically adopted from the lessons learned from coal seams through past experience, which might not help an efficient numerical simulation development.
In this study, how artificial intelligence assisted data driven models assist the hydraulic fracturing design in shale gas reservoir is discussed. It starts by collecting field data and generate a spatial-temporal database including reservoir characteristics, operational/production information, completion/stimulation data and other variables, Neural Network models are then developed to study the impacts of all parameters on gas production as well as perform history matching of the field history. The AI assisted model with acceptable matching of field data can be used to model different hydraulic fracturing design scenarios and provide predictions on well production.
Evaluating Completion Design Efficacy Using Poroelastic Pressure Responses in Offset Wells
Authors: Das Paloma , Kahn Charles , Coenen Erica 
Published: October 2019

Abstract
Operators continue their quest to better understand and design completion strategies to maximize reservoir contact and optimize well spacing. This paper presents a case study that analyzes completion design effectiveness, using pressure data acquired from isolated monitor stages on offset wells during treatment of adjacent wells. The method was employed on three wells of a seven-well pad in the Marcellus, to assess fracture growth and evaluate the performance of employing intra-stage and inter-stage diversion.
Poromechanically-induced pressure responses on isolated monitor stages on offset wells during treatment of an adjacent well, are compared to a fully coupled, three-dimensional, finite element effective stress model, to calculate dominant fracture geometries that correspond to the pressure response induced in the rock. The initiation points and ascending magnitudes of the responses approaching the isolated monitor stage qualify the performance of inter-stage diversion, whereas the fracture growth trends and geometries speak for the efficacy of the intra-stage diversion and overall stage design.
The first well utilized inter-stage diversion and dissolvable plugs to isolate stages; the second well utilized intra-stage diversion to improve cluster efficiency with regular frac plugs for zonal isolation; and, the third well employed regular frac plugs with no use of diversion. This presented a unique opportunity to compare and analyze the fracture growth rates, trends, and geometries, while applying inter-stage diversion and frac plug completion designs for zonal isolation on the same pad.
This paper is a comparative study to understand the value of using inter-stage diversion, along with dissolvable plugs in place of composite frac plugs, after every stage to attain zonal isolation. In addition, completed stages utilized different fluid designs, providing the opportunity to analyze the impact of fluid design on fracture growth trends and diverter performance. The results are interpreted using pressure data-derived fracture maps with production data, which point to the performance of various completion strategies, using an entirely new diagnostic method.
Developing a New Workflow to Study the Effect of Soaking Process on Shale Well
Authors: Ibrahim Ahmed Farid , Ibrahim Mazher , Pieprzica Chester 
Published: October 2019

Abstract
The most common stimulation technique of shale gas production is multistage hydraulic fracturing. However, the implementation of the technique brings in new formation damage considerations. Large quantities of water-based fracture fluids, over 75% of the injected volume, usually left unrecovered at the start of production that leads to permeability reduction and low productivity. Accidently, some operators found an improvement in gas recovery after shut in the wells after flowback due to pipeline restriction. They called this behavior as the soaking effect.
This study presents a workflow to evaluate the effect of the soaking process on the well performance after the hydraulic fracturing process in actual field cases. Waterflow back analysis was conducted for 21 well to estimate the effective fracture volume before and after the soaking process. Rate transient analysis (RTA) was conducted on the production data to estimate the stimulated reservoir volume (SRV) in each well. SRV and the enhanced recovery were correlated to the soaking time. Decline curve analysis for water and gas flow rates were conducted to estimate the estimated ultimate gas and water recovery (EURg, and EURw) before and after the soaking process.
An increase in the gas flow rate was observed with soaking time with low water production. SRV increased with the soaking process up to 53% of its initial value with shut-in the well for 180 days. EURw decreased by 52 % of its value before the soaking process, while EURg increased by 48%. Shut-in the well before gas-kick off after hydraulic fracturing operations negatively impact the well performance and the gas production can decrease by 22% even after soaking process for 315 days.
This study will present a methodology to evaluate the soaking process, and recommendations to improve the impact of the soaking process on well performance.
Extended Lateral Solutions for an Extremely Difficult Well Trajectory
Authors: Albert Larry , Booher Jason , Wilson Anthony , Hamilton Fraser , Hradecky Jason , Dunning Dustin , Pratosov Vadim 
Published: October 2019

Abstract
An E&P operator was developing a reservoir and planned a horizontal well in an area where zones above the target cause drilling problems when trying to build angle and land the horizontal lateral. The operator suffered drilling difficulties on offset wells; therefore, it was decided to change the drilling plan for this prospect. The new plan required drilling through the target reservoir, into the formations below and then drill back up dip to the target. After reaching the base at a measured depth of 14,000 ft. the well plan required drilling up at maximum of 114° until reentering the target reservoir. Because of faulting in the area and required well direction, the target reservoir was dipping up at ∼10° laterally in the direction of the horizontal drilling target. To maintain position in the reservoir, the well had to drilled at ∼100° deviation to a measured depth of 21,100 ft.
This wellbore trajectory made normal wireline plug and perforating completion operations extremely difficult. The wellbore trajectory meant high frictions on the wireline when coming off bottom. Also, due to the toe-up trajectory there was risk the wireline tools would slide down the inclined casing during and after plug setting and perforating. If the tool position could not be maintained there was risk the wireline cable could be entangled and a stuck tool could result. If the tools overrun the wireline cable the result could be wireline cable next to the perforating guns when detonated and wireline cable severed. The E&P operator needed to know if this challenge could be met.
Alternatives to pump down plug and perforating could be very expensive (estimated $millions): Abandon acreage,Continue drilling attempts building angle above the target,Reposition surface location and drill down dip,Reduce angle and shorten lateral in target, orCoiled tubing conveyed plug and perforating completion.
To meet the challenge several new methods and technologies developed for extended laterals were utilized. These products and methods included: advanced risk deployment modeling, jacketed wireline cable, addressable separation tool and downhole tension tool.
A New Gas-Content-Evaluation Method for Organic-Rich Shale Using the Fractionation of Carbon Isotopes of Methane
Authors: Cao Gaohui , Zhang Huanxu , Jiang Wenbin , Wu Sheng , Zhu Di , Lin Mian 
Published: October 2019

SummaryGas content is a key parameter for the determination of the gas resources in unconventional reservoirs. In this study, we propose a novel method to evaluate the gas content of shale through a new perspective: fractionation of carbon isotopes of methane. At first, a bicomponent gas–convection/diffusion/adsorption model (BG–CDAM) is successfully built with consideration of the flow and adsorption difference between 13CH4 and 12CH4 in the nanoporous shale. A detailed understanding of the mechanism of fractionation of the isotopes is obtained for the first time and the Knudsen–diffusivity difference is identified as the dominant factor for fractionation according to the different molecular weights of the isotopes. Then, the simulated results of BG–CDAM and the measured data from an isotope–logging test are combined to determine the unknown parameters for gas–content calculation. The proposed method for organic shale is valid and useful to obtain the quantitative component proportion in gas content, such as lost gas, degassing gas and residual gas, or free gas and adsorption gas. Thus, this method could provide a promising means for the identification of sweet spots in shale–gas reservoirs. Moreover, the method might have the potential to economically and rapidly evaluate the remaining resources in producing wells in future applications.
Advanced Surveillance Technique for Multi-Phase Sweep Efficiency Monitoring
Authors: Al-Qasim Abdulaziz , El Sheshtawy Mohamed , Kokal Sunil , Benlakhdar Noureddine 
Published: October 2019

Abstract
With maturing oil fields there is an increasing focus on improving the oil recovery factor and pushing the envelope toward a 70% target. This target is indeed very challenging and depends on a number of factors including enhanced oil recovery (EOR) methods, reservoir heterogeneities, displacement efficiency, and reservoir sweep. Other factors also play a role including vertical sweep due to flow behind the casing, well integrity issues, presence of conductive faults, or fractures. Proper surveillance performed to evaluate the injectant plume front, reservoir conformance, well connectivity, assessment of the integrity of wells, and other factors can be crucial for the success of the project and its future development.
The paper discusses special downhole logging techniques including a set of conventional multiphase sensors alongside high precision temperature (HPT) and high-definition spectral noise logging (SNL-HD). It was run to provide complete assessment of the injection – production distribution and any associated well integrity issues that might impair the lateral sweep of injectants into the target layer. This will be done for an injector and producer pair near the wellbore area. The operation was carried out with a tool string that contained no mechanical parts and was not affected by downhole fluid properties. It was conducted under flowing and shut-in conditions to identify flow zones and check fracture signatures. It also provided multiphase fluid velocity profiles.
The results of the survey allowed for in-depth assessment of borehole and behind casing flow, confirming lateral continuity, and provided an assessment of production-injection outside the pay zone. Results will allow for better well planning and anticipation of possible loss of well integrity that might impair production in the future. Combining the behind casing flow assessment with borehole multiphase flow distribution can be used for production optimization by sealing unwanted water contributing zones.
Low-Salinity Polymer Flooding in a High-Temperature Low-Permeability Carbonate Reservoir in West Kuwait
Authors: Al-Murayri Mohammed Taha , Kamal Dawood S. , Al-Sabah Hessa M. , AbdulSalam Tareq , Al-Shamali Adnan , Quttainah Riyad , Glushko Dan , Britton Chris , Delshad Mojdeh , Liyanage Jith , Dean Robert Matthew 
Published: October 2019

AbstractWhile polymer flooding has widely been used as a successful technology to improve mobility control and sweep efficiency in many oil reservoirs, its applicability under harsh temperature/salinity conditions and in low-permeability reservoirs has prohibitively remained a challenge.This study was aimed at investigating the feasibility of low-salinity polymer flooding in a very challenging reservoir located in Kuwait with low permeability (&lt; 10 mD), high temperature (113°C), high salinity (~239,000 ppm), high hardness (~20,000 ppm), and carbonate mineralogy. The evaluation was conducted through a series of systematic laboratory studies including polymer rheology, thermal stability, and transportability using coreflood tests.Our results highlight that the common constraints may be overcome by careful selection of polymer/cosolvent/pre-shearing and appropriate design of low-salinity polymer flooding.
High Throughput Catalyst Testing to Enhance Refinery Operations
Authors: Hakeem Abrar 
Published: October 2019

Abstract
An important aspect of refinery and petrochemical complex(s) are the catalytic units without which many processes are not possible. Catalyst selection in a refinery or petrochemical complex has a big impact on the yields, energy usage and provides with a competitive advantage by selection of better performing catalyst for the actual feedstock. To perform catalyst section, a comparative catalyst testing on a smaller scale unit is required. Previously, it used to be performed in a single flow conventional reactor unit, which is time consuming, non-effective and laborious in comparing more than two types of catalysts. As conventional catalyst testing takes long time, catalyst selection in refinery is often based on information shared by a Catalyst Vendor referred as "paper assessment". However, the use of high throughput technology enables accelerated catalyst testing (faster results) and facilitates the selection of the best catalyst in alignment with the timeline faced by the refinery in decision-making process. This enables identification of the best catalyst from different vendors based on actual performance of the catalyst and has a great potential to enhance operations. In addition, the use of high throughput catalyst testing unit enables opportunities with different experimental designs to develop kinetic models, to simulate reactors in series and to do stability tests in an effective manner.
Black Powder Removal from Oil Pipelines
Authors: Balhasan Saad , Omar Mohammed , Alhamoudi Hassan , Alzaabi Abdulrahman , Abdelwahab Salma 
Published: October 2019

Abstract
Of the total oil and gas supply, a significant share is transported through pipelines. Ultimately the level and quality of cleanness of pipelines greatly affect the transportation of oil and gas. Considering this, any obstacle in the pipelines will delay the transportation process and will consequently reduce the amount of oil and gas transported at a high cost. Remarkable issues that are related to black powders are the contamination of product, reduction in flow of oil and gas, and environmental hazards.
The main objective of this paper is to gain familiarity with the phenomenon of black powder, and based on the analysis design and builds a magnetic Nanoscale filtration/sorption system for crude oil treatment. A magnetic separation system is used for removal of iron and heavy metals from crude oil. The prime function of the radial field magnetic separation system is the breaking-down of black powder particles to submicron levels in full flow. Moreover, the paper has studied the enhancement of nanoparticle technology by using the graphene nanoparticles to improve the separation efficiency of the magnetic separation system. The graphene nanoparticles have enhanced the magnetic separation system. The resistivity meter has been used to measure the resistance of the oil, before being contaminated with black powder and after, in each step of the experiment. It has been observed that higher resistance leads to lower values of black powder.
The analysis suggests that one stage of magnetic separation is more efficient than two stages. Measurement shows that with one stage magnetic separation procedure, the resistance of the oil sample, with black powder, increased from 2157 kΩ to 2969 kΩ, before and after the magnetic separator. The separation of black powder has estimated by 22%, and the magnetite material decreased by 16 gm. However, the resistance of the oil sample, with graphene nanoparticles, increased from 1799 kΩ to 2661 kΩ, before and after the magnetic separator. The separation of black powder has estimated by 24%, the amount of the magnetite material decreased by 19.58 gm. The 2% increase in the efficiency of the system can be attributed to the use graphene nanoparticles.
Investigation of Low Salinity EOR: Application for Kuwaiti Reservoir
Authors: AlAmer Rawan , Al Ajmi Abdullah , Al Qahtani Mesferah , Gharbi Dr Ridh 
Published: October 2019

Abstract
This paper investigates the applicability of Low Salinity (LoSal) EOR for a Kuwaiti reservoir. Many reservoirs in the Middle East are not producing satisfied results after depletion methods for a long time of production. Therefore, new management and production strategies must be determined in order to meet the global market demand for oil, which can be done using Enhanced Oil Recovery (EOR) techniques. In Kuwait, one of the EOR methods that could be applied is the use of Low-Salinity (LoSal) Water Flood.
Results from previous research have clearly shown that LoSal water injection has a significant impact on oil recovery. Although there are many LoSal experimental results reported in the literature, the process mechanisms and the prediction modeling are yet to be fully investigated and understood. As a result, further experimental work is needed in order to be able to develop reliable prediction tools.
The research in this paper is an integrated study combining laboratory work to assess the performance of LoSal water flood using live crude, reservoir brine and native core with wettability conditions restored. The core flooding phase will conduct series of low salinity water flood experiments, design of Salt type and concentration. The performance of LoSal will be compared to different salinities water flood based on reservoir water salinity.