bluuebunny/crossref_metadata_2025_split huggingface dataset:
Premium Connections Fatigue Assessment Methodology Fit for Multi-stage Hydraulic Fracturing Operations
Authors: Zara Emanuel Mariano , Grittini Santiago Javier , Rodriguez Jordan Gonzalo , Perello Leandro , Sanders Mattew 
Published: September 2021

Abstract

Objectives/Scope
During casing installation and drilling operations, Oil Country Tubular Goods (OCTG) strings are often rotated inside deviated wellbores, generating cyclic bending loading that could lead to fatigue damage. This phenomenon has been previously studied and understood. The completion of multistage fractured horizontal wells (MFHW) involves tens of fracture operations (an ever growing number) as part of the stimulation program in order to maximize production. These fracture operations involve a combination of cyclic pressures and tension loading in the production casing, through which they are conducted, with maximum loads often repeatedly reaching the upper limit of the pipe body performance ratings. This process of cyclic pressure and tension loading near the upper limit of the pipe body performance is the subject of this work. In unconventional plays, where MFHW are the standard approach, both cyclic bending due to rotation and cyclic burst and tension due to multiple fracturing operations are applied on OCTG strings. This combination may lead to a failure mode in which a crack opens due to material fatigue during rotation or fracturing cycles, and subsequently propagates (to failure) during the demanding fracturing stages.

Methods, Procedures, Process
As it would be expected during any technological evolution, the industry has seen an increase in casing failures during hydraulic fracturing, often not explainable by the current understanding of loads scenarios present in wellbores. Some of these events could be associated to the failure mode described above. Despite the potential risk introduced by this failure mode, to date, there is no standardized testing methodology available to evaluate the resistance of pipes and connections to this loading sequence.

Results, Observations, Conclusions
In order to cover this gap, a testing sequence aimed at replicating actual operating conditions was developed and deployed by the authors. This includes evaluating the resistance of a premium connection to rotation through a curved hole, and subsequent burst and tension cycles. The methodology and results are presented in this paper.

Novel/Additive Information
Through this testing approach, operators, manufacturers, and laboratories alike, can ensure the performance and reliability of OCTG, which are key elements in the well construction process. As main observations, all tested specimens successfully passed this very demanding testing sequence, aimed to replicate operative conditions during installation and subsequent stimulation operation.
ARPR Assurance Standardization and Streamlining: A Digitalization and Automation Approach
Authors: Yaaribi Zainab , Hooti Huda , Al-Jumah Ali 
Published: September 2021

Abstract
This paper will discuss the improvement done to standardise the process of the Annual Review of Petroleum Reseources (ARPR) Process across PDO. How Digitalisation of the process saved time and reduced resources need to conduct such lengthy and complex exercise which done annually.
Many stakeholders are involved in the process, where applying standard digital solution "ARPR assurance tool' eliminated waste and accelerated progress, while following a Standard Operating Procedue (SOP).
Two-Phase Type-Curve Analysis of Flowback Data from Hydraulically Fractured Hydrocarbon Reservoirs
Authors: Zhang Fengyuan , Emami-Meybodi Hamid 
Published: September 2021

Abstract
This study presents a new type-curve method to characterize hydraulic fracture (HF) attributes and dynamics by analyzing two-phase flowback data from multi-fractured horizontal wells (MFHWs) in hydrocarbon reservoirs.The proposed method includes a semianalytical model, as well as a workflow to estimate HF properties (i.e., initial fracture pore-volume and fracture permeability) and HF closure dynamics (through iterating fracture compressibility and permeability modulus).The semianalytical model considers the coupled two-phase flow in the fracture and matrix system, the variable production rate at the well, as well as the pressure-dependent reservoir and fluid properties. By incorporating the contribution of fluid influx from matrix into the fracture effective compressibility, a new set of dimensionless groups is defined to obtain a dimensionless solution for type-curve analysis. The accuracy of the proposed method is tested using the synthetic data generated from six numerical simulation cases for shale gas and oil reservoirs. The numerical validation confirms the unique behavior of type curves during fracture boundary dominated flow and verifies the accuracy of the type-curve analysis in the characterization of fracture properties. For field application, the proposed method is applied to two MFHWs in Marcellus shale gas and Eagle Ford shale oil.The agreement of interpreted results between the proposed method and straight-line analysis not only demonstrates the practicality in field application but also illustrates the superiority of the type-curve method as an easy-to-use technique to analyze two-phase flowback data. The analysis results from both of the field examples reveal the consistency in the estimated fracture properties between the proposed method and long-term history matching.
Efficient Modeling of Proppant Transport During Three-Dimensional Hydraulic Fracture Propagation
Authors: Wang Jiacheng , Olson Jon 
Published: September 2021

Abstract
We propose an adaptive Eulerian-Lagrangian (E-L) proppant module and couple it with our simplified three-dimensional displacement discontinuity method (S3D DDM) hydraulic fracture model. The integrated model efficiently calculates proppant transport during three-dimensional (3D) hydraulic fracture propagation in multi-layer formations. The results demonstrate that hydraulic fracture height growth mitigates the form of proppant bed, so the proppant placement is more uniform in the hydraulic fracture under a smaller stress contrast. A higher fracturing fluid viscosity improves the suspension of proppant particles and generates a fracture larger in height and width but shorter in length. Lower proppant density and particle size reduce the proppant settling and create more uniform proppant placements, while they do not affect the hydraulic fracture geometry. Moreover, a larger proppant particle size limits the accessibility of the hydraulic fracture to the proppant, so the larger proppant particles do not fill the fracture tip and edge where the fracture width is small.
Vaca Muerta's Productivity and Economic Performance. 7 Years in Review
Authors: Gilardone Carlos R. , Canel Carlos A. , Albuquerque Luisa , Ruiz Benitez Manuel I. , Cabello Ariel 
Published: September 2021

Abstract
Vaca Muerta is an unconventional reservoir located in Argentina. Since 2014, 397 horizontal wells have been drilled in this formation. The scope of this paper is to summarize the evolution of the productivity and the economics of these wells from 2014 until 2020.
The methodology consisted in analyzing the results of the wells grouped by drilling campaign extracting the main parameters such as peak oil rate, cumulative oil at 365 days, number of fracture stages and length of the drain. After the extraction of these parameters we calculated each well's EUR using a modified hyperbolic function. A statistical analysis of the results was performed in order to calculate a "Type Well" for each drilling campaign. An economic evaluation for each campaign was then generated in order determine the "Type Well" economics.
Once this was achieved we calculated the production profile of an "Economic Type Well" for each campaign defining this as the well which would generate an NPV=0$ at a discount rate of 10%. This was used to determine how many wells were economical for each year.
The results of this study show the big impact on the productivity generated by the increase in well length and the number of frac stages revealing the progression of the "Learning curve" for the Vaca Muerta basin including the reduction in Capital Expenditures per well.
At present, Vaca Muerta represents an opportunity as a profitable play due to the high productivity of the reservoir and low risk. Nevertheless, there is still room for improvement in the wells' cost according to the results of this study.
This paper presents the evolution of the economics and the risk performance of Vaca Muerta.
Modeling Boundary-Dominated Flow in Hydraulically-Fractured Wells
Authors: Sheikh Hafiz Mustafa Ud Din , Lee W. J. , Jha H. S. 
Published: September 2021

Abstract
This paper presents a simple method to model boundary-dominated flow in hydraulically fractured wells, including horizontal wells with multiple fractures. While these wells are almost always producedat more nearly constant BHP rather than constant rate, use of material-balance time transforms variable-rate production profiles to constant-rate profiles, allowing us to use the pseudo-steady-state (PSS) flow equation for modeling. However, the PSS equation requires use of shape factors in applications, and shape factors available in the literature are available only for square-shaped bounded reservoirs with hydraulic fractures. In this work, we derived shape factors for wells centered in rectangular-shaped drainage areas with different length-to-width aspect ratios.
The superposition principle can be used to transform transient radial flow and transient linear flow solutions into bounded reservoir solutions. At large times (when boundary-dominated flow is established), results from these solutions are similar to those obtained from the PSS equation. Therefore, for a pre-defined reservoir geometry, pressure drop values from superimposed transient flow equationscan be substituted back into the PSS equation to calculate shape factors for that reservoir geometry.We used shape factors previously presented by other authors for square drainage areas to validate themethod before applying it to calculate shape factors for more general drainage area configurations.
We present shape factors for different fracture half-length to fracture-spacing ratios ranging from 0.2 to 10. Calculated shape factors, when plotted against the fracture half-length to fracture-spacing ratio, produced a smooth curve which can be used to interpolate shape factor values for other fracture configurations. We present applications of this methodology to example low-permeability wells.
The use of the PSS equation for wells with vertical fracturescan be extended to multi-fractured horizontal wells (MFHWs) by incorporating the number of fractures in the equation; hence, shape factorsderived for wells with vertical fractures can also be used for MFHWs. Although our results are rigorously correct only for fluids with constant compressibility, use of pseudo-pressure and pseudo-time transformations extend application to compressible fluids, notably gases. Using the PSS equation in production data analysis allows us to calculate contributing reservoir volume and drainage area in a simple manner not requiring use of specialized software.
Fracture Permeability Estimation Under Complex Physics: A Data-Driven Model Using Machine Learning
Authors: He Xupeng , Zhu Weiwei , Santoso Ryan , Alsinan Marwa , Kwak Hyung , Hoteit Hussein 
Published: September 2021

Abstract
The permeability of fractures, including natural and hydraulic, are essential parameters for the modeling of fluid flow in conventional and unconventional fractured reservoirs. However, traditional analytical cubic law (CL-based) models used to estimate fracture permeability show unsatisfactory performance when dealing with different dynamic complexities of fractures. This work presents a data-driven, physics-included model based on machine learning as an alternative to traditional methods. The workflow for the development of the data-driven model includes four steps. Step 1: Identify uncertain parameters and perform Latin Hypercube Sampling (LHS). We first identify the uncertain parameters which affect the fracture permeability. We then generate training samples using LHS. Step 2: Perform training simulations and collect inputs and outputs. In this step, high-resolution simulations with parallel computing for the Navier-Stokes equations (NSEs) are run for each of the training samples. We then collect the inputs and outputs from the simulations. Step 3: Construct an optimized data-driven surrogate model. A data-driven model based on machine learning is then built to model the nonlinear mapping between the inputs and outputs collected from Step 2. Herein, Artificial Neural Network (ANN) coupling with Bayesian optimization algorithm is implemented to obtain the optimized surrogate model. Step 4: Validate the proposed data-driven model. In this step, we conduct blind validation on the proposed model with high-fidelity simulations. We further test the developed surrogate model with newly generated fracture cases with a broad range of roughness and tortuosity under different Reynolds numbers. We then compare its performance to the reference NSEs solutions. Results show that the developed data-driven model delivers good accuracy exceeding 90% for all training, validation, and test samples. This work introduces an integrated workflow for developing a data-driven, physics-included model using machine learning to estimate fracture permeability under complex physics (e.g., inertial effect). To our knowledge, this technique is introduced for the first time for the upscaling of rock fractures. The proposed model offers an efficient and accurate alternative to the traditional upscaling methods that can be readily implemented in reservoir characterization and modeling workflows.
A Field Pilot of Waterflooding Conformance Control in Tight Oil Reservoir with Biotechnology
Authors: Liu Songyuan , Jin Xiaochun , Liu Deji , Xu Hao , Zhang Lidong , Zhou Xiaosong , Huang Peng , Thomspson James , Lu Bo 
Published: September 2021

Abstract
Traditional Microbial Enhanced Oil Recovery (MEOR) technology assumes the oil recovery is increased by the biosurfactant generating by the subsurface bacteria. However, we identified that increased recovery factor is mainly contributed by stimulating the indigenous bacteria to plug the preferred waterflooding channels, which was proved at laboratory and some high-permeable oilfield, but never implemented in the waterflooding of tight oilfield. This paper presents a comprehensive study on Bio-diversion technique by stimulating indigenous bacteria covering lab research and filed operation lasting 18 months. The lab research comprised: (1) feasibility research using modified recipe and field sample on the stimulation of indigenous microorganisms; and (2) Evaluation of effectiveness of the stimulation based on lab results. A field pilot, consisting of 10 injectors, 10 producers, injecting and producing from multi-zones, reservoir temperature is about 160 F, permeabilities range from 30 md to over 100 md, daily water injection rate is about 2,000 BWPD, pre-treatment water cut is over 90%. It is observed that the water cut has decreased from 98% to 80% gradually (3-6 months after injection). Besides, the water injection index test indicates that the injection profile becomes more evenly after 9 months of microbial nutrient injection because the stimulated bacteria reduce the permeability of more permeable zones and reduce the permeability heterogeneity in the vertical direction. Sharing the field results with the industry may inspire the operators to consider one alternative environmentally friendly and cost-effective approach to increase the recovery factor of tight oil reservoirs. From the technical viewpoint, the field pilot proves that the major mechanisms of MEOR is sweeping the unswept oil by injecting the microbial nutrient to the reservoir to stimulate the indigenous bacteria to block the preferred waterflooding channels.
Automated Subsurface Knowledge ASK Thamama Retrieval Engine Driven by Conversational Text Analytics and NLP - Lessons Learned in Managing Large Volume of Documents in Abu Dhabi Assets
Authors: Braik Fahed Mubarak , Al Shehhi Abdulla Sulaiman , Saputelli Luigi , Mata Carlos , Badmaev Dorzhi , Khan Salman , Rahman Fariz 
Published: September 2021

Abstract
The purpose of this paper is to communicate the experiences in the development of an innovative concept named "ASK Thamama" as an automated data and information retrieval engine driven by artificial intelligence techniques including text analytics and natural language processing. ASK is an AI enabled conversational search engine used to retrieve information from various internal data repositories using natural language queries. The text processing and conversational engine concept is built upon available open-source software requiring minimum coding of new libraries.
A data set with 1000 documents was used to validate key functionalities with an accuracy of 90% of the search queries and able to provide specific answers for 80% of queries framed as questions.
The results of this work show encouraging results and demonstrate value that AI-enabled methodologies can provide natural language search by enabling automated workflows for data information retrieval. The developed AI methodology has tremendous potential of integration in an end-to-end workflow of knowledge management by utilizing available document repositories to valuable insights, with little to no human intervention.
How to Space SAGD Well Pairs for Optimal Performance
Authors: Zargar Zeinab , Farouq Ali S. M. 
Published: September 2021

Abstract
Steam-Assisted Gravity Drainage (SAGD) is a remarkably successful process for the tar sands (oil sands). Two closely spaced parallel horizontal wells, injector above the producer, form a SAGD well pair. Steam is injected to provide heat to the reservoir oil and mobilize it. The low viscosity oil drains down to the producer under the gravity effect. Parallel well pairs 1000 m long are utilized in the process, spaced 100 m apart horizontally almost in all projects.
In this work, an analytical model for the SAGD process is introduced by coupling heat and fluid flow and constitutive equations. A moving boundary, counter-current flow approach is used for the steam chamber rise and subsequent sideways expansion. The model is unique because it assumes the steam injection rate is constant and it permits modeling of the late phase of SAGD when adjacent well pair interference occurs. This leads to a reduction in heat loss to the overburden and a decline in oil production rate. This study examines the question of optimal well pair spacing in relation to the formation thickness and in-place oil. The effect of other variables on SAGD performance is investigated.
A case study was performed using Christina Lake oil sand properties to show how the project performance varies under different senerios involving well pair spacing, reservoir thickness, steam injection rate, and steam quality. Results show that, in evaluating a SAGD pad performance, as the spacing is increased, the cumulative oil production decreases, with a simultanous increase in the cumulative steam-oil ratio at the same steam injection rate. However, a smaller portion of injected heat is lost to the overburden. It is concluded that a smaller well spacing requires more wells to deplete the whole pad area. On the other hand, a larger pattern well spacing affects oil recovery and heat consumption. Different conclusions are derived for the same pattern well spacing value using a single well pair model and pattern well pair configuration. Results also show that SAGD well pair spacing can be increased with an increase in formation thickness.
The computational procedure is simple and makes it possible to examine a series of options for well spacing for a given set of conditions. This study presents for the first time an analytical relation between SAGD pattern well pair spacing and oil recovery.
Proppant Transport in Hydraulic Fractures by Creating a Capillary Suspension
Authors: Bello Ayomikun 
Published: September 2021

Abstract
Slick water fracturing fluids with high viscosity and minimal friction pressure losses are commonly employed in hydraulic fracturing nowadays. At the same time, high injection rates can be used to perform hydraulic fracturing to get the calculated fracture sizes.
The conventional algorithm for conducting a standard proppant hydraulic fracturing includes performing a pressure test using a linear gel without a trial proppant pack to determine the quality of communication with the formation and the initial parameters of the fracture; and performing a mini-hydraulic fracturing on a cross-linked gel with a trial proppant pack (1000 - 2000 kg) to assess the parameters of the fracture development used to correct the design of the main hydraulic fracturing operation.
However, in complex geological conditions associated with the presence of small clay barriers between the target formation and above or below the water-saturated layers, as well as in low-productive formations, this conventional method of conducting hydraulic fracturing operations using high-viscosity fluids is not always suitable. Hydraulic fracturing in thin-layer formations is associated with a significant risk of the tightness established by the fracture being broken, as well as fluids contained in the underlying or overlying layers being involved in the drainage process.
Hydraulic fracturing in low-productive formations creates fractures that are similar in shape to radial fractures, reducing the efficiency and profitability of the impact due to inefficient use of materials and reagents. The main task in this situation is to limit the height of the fracture development and increase their length. It is necessary to use low-viscosity fracturing fluids with a high ability to transfer proppants to reduce the specific pressure in the fracture and control the height of the rupture. The goal of this research is to develop such fluid.