bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benefits of Novel Preformed Gel Fluid System in Proppant Placement for Unconventional Reservoirs
Authors: Zhou Jia , Sun Hong , Qu Qi , Guerin Michael , Li Leiming 
Published: June 2014

Abstract
Post-treatment production analyses after hydraulic fracturing with crosslinked gel or slickwater often indicate that the treatment did not achieve the designed fractured area, which could be attributed to non-ideal proppant placement in the fracture. Although crosslinked gel provides good proppant suspension, it may not provide the desired proppant transport under downhole conditions. It is also difficult to clean up and thus induces gel damage into the proppant pack and formation. Slickwater treatment reduces gel damage, but proppant settling and banking problems can reduce the chance of achieving optimal fracture conductivity. Several proppant placement techniques have been developed to generate highly conductive paths for hydrocarbons to flow from an unconventional reservoir to the wellbore, such as hybrid fracturing, ultralightweight proppant delivery, and reverse hybrid fracturing.
This paper demonstrates a novel fracturing fluid and its nearly perfect proppant transport characteristics. An engineered method of applying such fluids to optimize proppant placement and maximize fracture conductivity is discussed. The novel fracturing fluids are based on preformed gel fluids. When properly selected, the fluids can ideally suspend proppant under downhole conditions and carry all types of proppants into the fracture. This leads to better transverse and vertical placement of proppant in the fracture and significantly increases the fractured surface area, which is one of most important factors in unconventional reservoir production. The degradability of the fluid can be controlled by reservoir temperature, fluid pH, or breaker loading, which leads to optimized proppant pack conductivity.
This paper discusses the evolution of the technology and laboratory testing results for this unique fluid system. The system has applications in areas requiring high fractured surface area and high regained conductivity, such as unconventional liquids-rich formations.
Is It Possible to Do Unlimited Multi-Stage Fracturing Economically?
Authors: Yuan Feng , Blanton Eric , Palmer Chris , Andersen Clayton , Grogan Alison 
Published: June 2014

Abstract
Over the last decade or so, unconventional shale resources have been playing an increasingly important role in hydrocarbon production due to advanced drilling, fracturing and completion technologies enabling the recovery of previously uneconomic reserves, and multi-stage fracturing technology has been widely used to exploit them in the North American oil & gas industry. During that time the completion process has been evolving, starting with the Plug and Perf method and then with multiple ball seat size actuated sliding sleeves gaining attention. However both methods have their drawbacks, the former requiring multiple re-entries and mill out operations, the latter having a limited number of fracturing stages due to the graduated seat sizes needed and the probability of the need for milling out the seats upon completion to remove flow restrictions (Wozniak 2010).
As a result of these drawbacks, the industry has been driven to the development of some high-performance multi-stage fracturing completion systems which are emerging in the marketplace as alternatives to both plug and perf and traditional ball-activated frac sleeves. Three such unlimited multi-stage fracturing systems, which have been developed in recent years, can be cemented in place if desired and have a full-bore internal diameter (ID) or as close as possible to the host tubular string after fracturing and do not need milling-out operations, reducing overall completion time and improving fracturing and production efficiency. These include: 1)Coiled Tubing (CT)-Operated sleeve – this incorporates a Bottom-Hole Assembly (BHA) which is used to isolate the target zone and shift the sleeve open with fracturing being performed down the CT/Casing annulus on an nearly unlimited number of sleeves.2)An evolutionary ball-activated frac system – this uses a single size ball and ball seat for each zone, which allows an essentially unlimited number of frac stages.3)Radio-Frequency-Identification (RFID) frac sleeves – by simply dropping RFID tags in the completion string, the RFID frac sleeve system can be run with an unlimited number of frac stages.
This paper will review developments in multi-stage fracturing completions, describe in detail their unique features and capabilities which are not available in earlier systems and present simulations of frac efficiency with quantitative comparisons. The analysis will indicate that these three new frac sleeves technologies can be used to optimize hydraulic fracturing operations in both horsepower and stimulated reservoir volume while dramatically reducing overall completion costs.
Reservoir Heterogeneity in Upper Carboniferous Tight Gas Sandstones: Lessons Learned From an Analog Study
Authors: Wuestefeld P.. , Hilgers C.. , Koehrer B.. , Hoehne M.. , Steindorf P.. , Schurk K.. , Becker S.. , Bertier P.. 
Published: June 2014

Abstract
Upper Carboniferous sandstones in NW-Germany consist of thick successions of cyclic deposits and are major tight gas reservoirs. This study presents the heterogeneity exposed in a large quarry near Osnabrück, Germany, which contains faulted and jointed fourth-order coarse- to fine-grained tight sandstone cycles separated by anthracite coal seams. First, we characterize the rocks and the lateral variation of rock properties such as porosity, diagenesis and structural inventory. Than we test whether the quarry may act as a tight gas reservoir analogue to better constrain input data for reservoir modeling. The tight sandstones are intensely compacted and cemented with quartz and generally characterized by low matrix porosities &lt; 8 % (He-pycnometry on plugs and cuttings) and very low permeabilities (&lt; 0.01 mD). Porosity is generally secondary intraparticle, formed by detrital and authigenic carbonate dissolution and dissolution of feldspars. Matrix porosity significantly increases up to 25% in corridors around faults. Main rock types can be distinguished by spectral gamma ray in the quarry. Quartz veins and fault mineralizations indicate fluid flow within and around faults. Normal faults show bands of clay smear and gouge, forming compartments. Fractures were analyzed in a 50 x 50 m section of the quarry wall using LIDAR laser scanning. This digitized quarry face also allows the characterization of the lithology and quantitative measurement of bedding, fracture and fault orientation data in inaccessible areas. Our high-resolution field analogue enables a better understanding of tight sand reservoir properties and reservoir quality at a sub-seismic scale, considering both the change of porosity during diagenesis and the formation of structures. Results may be used to develop data-driven exploration strategies and improved development options for similar subsurface tight gas reservoirs, especially in Northern Germany.
De-Risking Shale Plays and Assessing By-Passed Pay Potential in the Netherlands
Authors: Lutgert Jan , Greiss Rita-Michel , Hughes Chris 
Published: June 2014

Abstract
This paper summarizes the work performed by EBN together with NuTech Energy Alliance for the Netherlands regional study, which aims to address the underexplored pay potential covering both onshore and offshore Netherlands. The paper provides the technical proceedures involved and the usage of available public domain well data for the Netherlands regional field study in order to fulfill the study's two main objectives. First main objective being to identify and analyze the shale play opportunities in unconventional reservoirs of the Lower Jurassic Posidonia Formation and the Namurian Geverik member as well as other shale & marl sections in the area. The second objective is to identify bypassed hydrocarbon opportunities in conventional reservoir sections through onshore and offshore Netherlands.
The Netherlands regional study provides insight into reservoir potential, geological and petrophysical properties of all formations based on innovative petrophysical well data analysis that were applied to 116 representative wells across the area.
Unlocking Future Heavy Oil Development in the North Sea: A Well Testing Success in the Kraken Field
Authors: Beck D.. , Shumakov Y.. , Hetherington G.. , Ovchinnikov V.. 
Published: June 2014

Abstract
There is an increasing hydrocarbon demand from a diminishing resource base in the North Sea. Technological advancements and government support coupled with activities in the UK Continental Shelf are enabling the development of untapped heavy oil resources. Heavy oil appraisal-well testing has always been a primary source of information for reservoir characterization, well deliverability, and evaluation of potential technologies for further application in field development.
Until recently, heavy oil well tests have been limited and deemed challenging because of the complexities associated with the nature of the heavy crude and lack of a proven well-test concept with a strong track record. Technical challenges in heavy oil well testing include designing the most appropriate ESP-DST string, maintaining fluid mobility through the surface test spread, achieving efficient separation for safe and environmentally friendly disposal, and obtaining accurate flow rate measurements. With recent technological developments, enhancements in the well test design, and appropriate equipment selection, a heavy oil well test has been engineered for success by bringing together multi-disciplinary teams and emphasizing the importance of proper job design and operational collaboration.
This paper describes the evolution of the practically proven heavy oil well-testing methodology applied in the Kraken heavy oil field with 15° API crude located in the UK Continental Shelf. A horizontal well was successfully tested in 2011 by using an innovative ESP-DST string, a dual-energy gamma ray venturi-type multiphase flow meter, a new burner system and realtime data monitoring. This paper also presents the lessons learned for obtaining high quality data to extract critical reservoir information with confidence through pressure transient analysis. This success paves the way for confident development drilling to commence on the Kraken field and also proves the heavy oil well testing concept for future applications in the North Sea heavy oil fields and elsewhere.
Modeling Multiple Hydraulic Fractures Interacting with Natural Fractures Using the Material Point Method
Authors: Aimene Yamina E. , Nairn John A. 
Published: June 2014

Abstract
This paper describes use of the Material Point Method (MPM) for modeling the propagation and interaction of multiple hydraulic fractures (HF) with natural fractures (NF). First the method is used on a laboratory experiment involving one HF and one NF positioned at different angles from the maximum horizontal stress. Various geomechanical simulations are performed by varying the stress anisotropy and the angle of the NF to study the remote impact of the HF on the NF. The results show the various levels of influence a HF has on a NF with a general trend being a higher influence for lower anisotropy ratio and lower NF angles. For an anisotropy equal to 1 and a NF with angle of 90 degrees, the detailed NF opening mechanism before, during and after the HF crosses a NF is studied in detail. The MPM simulations show that under the influence of the HF, the NF opening starts before the HF reaches it and even before the HF propagation. This result could help better understand the microseismic events recorded farther from the HF tip. Finally, a new workflow that integrates geophysics, geology, geomechanical simulations using MPM and completion engineering is described and validated with a real and complex Marcellus gas shale well. The workflow uses a seismically derived fault attribute map as input into the Continuous Fracture Modeling (CFM) approach to generate an Equivalent Fracture Model (EFM). The MPM geomechanical simulation of multiple hydraulic fractures propagating in the input EFM model leads to estimation of a strain field and J integral at each frac stage with a computation time not exceeding a few hours. The application of this workflow to an anomalous Marcellus gas well, shows that the estimated strain model has many striking similarities with the interpreted microseismic. The shape and the extent of the geobodies seen in the simulated strain field are very similar to those seen in the microseismic. Furthermore, the predicted J integral at each frac stage is correlated well with the density of the microseismic events at the same frac stage. The entire workflow takes only few hours thus making it suitable for any completion engineer designing his well. The new workflow brings improved and realistic geomechanics into the G&G world by providing new insights into the complex behavior of multiple hydraulic fractures propagating in a naturally fractured reservoir. This new insight will provide an additional powerful tool for an integrated approach that combines G&G, geomechanics and engineering for the imaging of sweet spots and reliable estimates of well performance thus allowing improved and economical fracing and development of shale reservoirs.
Development of an Optimized Completion Strategy in the Vaca Muerta Shale with an Anisotropic Geomechanical Model
Authors: Ejofodomi E. A. , Varela R. A. , Cavazzoli G.. , Velez E. I. , Peano J.. 
Published: June 2014

AbstractIn the Vaca Muerta shale of the Neuquén basin, Argentina, the most prolific intervals tend to be the most difficult to hydraulically fracture because of the abnormally high fracture gradients present in some parts of the basin. Thus, it becomes very important to have a good understanding of the anisotropic geomechanical properties of this heterogeneous formation prior to developing the completion strategy.A calibrated, anisotropic 1D mechanical earth model (1D MEM) was developed and used to optimize the completion strategy for a vertical well in the Vaca Muerta shale. The output from the 1D MEM, including the principal stresses, anisotropic elastic properties, pore pressure, and rock strength, were used to define the reservoir intervals with the best characteristics for initiation, propagation, and maintenance of a conductive complex fracture network. Next, the reservoir intervals with the highest hydrocarbon generation tendency were determined from petrophysical and image logs acquired in the well. This formed the basis for selecting the optimum number of stages and perforation strategy for the well.Sensitivity analysis revealed the impact of the hydraulic fracture properties on the production performance. The analysis showed that higher fracture conductivity greatly improves the well performance in the deeper Vaca Muerta intervals, whereas larger fracture surface area is more beneficial across the shallower intervals. Thus, a unique completion strategy was developed for each interval to optimize the well performance. Three hydraulic fracture stages were planned initially, but because of casing limitation, only the first stage was executed. A time-lapse acoustic measurement acquired from the well corroborated the propped fracture height predicted during the completion design phase.The study showed that proper characterization of the anisotropic geomechanical behavior of the Vaca Muerta formation improves the development of a completion strategy, which ultimately optimizes economic performance of the well.
Automated Modeling by Recognition
Authors: Anvar Amir , Fisher Christopher 
Published: June 2014

Abstract
Facility 3D Computer Aided Design (CAD) models are not updated regularly, or at all, once a facility goes into operations. In many brownfield assets, there is no 3D facility model to begin with. As-built models are required as a foundational technology that, through the virtual and visual experience of dynamic 3D models, will enable several business functions such as training and simulation, operations monitoring and surveillance, design modifications and project execution planning support, and hazard analysis and system reviews. In addition, the regulatory environment is changing and could result in the use of immersive 3D environments for operator competency assurance and various other compliance requirements, similar to the airline industry.
While there are existing model update processes, such as automated pipe recognition, the creation of the as-built model is a very time-consuming and labor-intensive activity that prohibits broader adoption and use, especially on large offshore Major Capital Projects.
The current objective of our R&D effort is to build an innovative modeling system, which combines data-driven and primitive-based modeling techniques, to automate the creation of 3D geometry models and texture maps from LiDAR (Light Detection and Ranging) point cloud data. In essence, this system acts as a highly automated bridge between "dumb" laser scan data and "intelligent" 3D models, enabling pervasive use of as-built models throughout an asset’s lifecycle.
Identification of Reservoir Analogues in the Presence of Uncertainty
Authors: Perez-Valiente M. L. , Martin Rodriguez H. , Santos C. N. , Vieira M. R. , Embid S. M. 
Published: June 2014

Abstract
We propose and evaluate a new methodology and tool for the identification of reservoir analogues of a target reservoir, given a database of known reservoirs. In particular, we focus on the common situation where some of the key properties of the target reservoir are unknown. This situation introduces uncertainty into the identification procedure. Therefore, an important step in our methodology is to characterize this uncertainty, so that it can later be considered when estimating production potential and capturing the associated risk.
The proposed methodology is composed of a sequence of five steps: Data Preprocessing, Key Parameters Selection, Statistical Learning, Similarity Ranking and Uncertainty Characterization. The first step consists of the analysis and pre-processing of the available database. During Key Parameters Selection, properties with largest impact in the case to be evaluated are identified. In the third step, unknown key properties of the target reservoir are estimated using different statistical learning techniques. In the Ranking step, a similarity function is applied to the database, generating a similarity ranking. Finally, in the Uncertainty Characterization step nonparametric methods are used to estimate probability density/mass functions to characterize the uncertainty in the properties estimated through analogous reservoirs.
We perform experiments to assess both the quality of property prediction and the quality of the selected analogues. We report results produced by five different machine learning algorithms using leave-one-out cross-validation. According to our results, Decision Trees was the most effective algorithm for categorical properties, while Regressive Support Vector Machines produced the best results for numerical properties. We also show detailed results for the Casablanca oil field as a target reservoir, which is a mature carbonate reservoir very well known by Repsol.
Our methodology allows the identification of analogues for newly discovered reservoirs with limited information. An important additional outcome is the estimation of unknown properties such as recovery factor and production mechanism, and their associated uncertainties, which support the field development plant.
An Innovative Approach To Select Shallow Casing Points Remotely, Utilizing Real-Time WITSML Data
Authors: Khudiri Musab M , Oteibi Munahi D , Gadri Waleed I , AlSanie Faisal S , Kashif Muhammad , Hickin Gary 
Published: June 2014

Abstract
This paper describes the continued & increasing impact of WITSML on the Drilling & Workover real time operations. The Wellsite Information Transfer Standard Markup Language (WITSML) is an Industry Standard that is used for transmitting GeoTechnical Data from the Wellsite to specialised databases. Saudi Aramco has been and remains to be the largest user of WITSML and is the Leader in the development of innovative techniques that improve Well Safety and Efficiency.
Saudi Aramco Drilling & Exploration teams have commenced a project of Picking Shallow Casing Points Remotely from their corporate offices. From past experiences we found that sending wellsite geologists to rig sites to select these Casing Points has always required people which could be utilized for other frontline exploration jobs. Due to the remote locations Saudi Aramco are also eliminating the risks associated with these field trips. Saudi Aramco teams determined to utilize the real-­-time data transfer and pick those shallow Casing Points from the office. Across these shallow sections, loss circulation is more likely to happen which means rate of penetration (ROP) data is the only entity that we depend on in order to pick these shallow Casing Points. Based on this understanding, and based on the fact that we can easily get the ROP data of the pilot well and also having ROP data of the offset wells, we see the great benefit of starting such project. In this trial project, Drilling, GOC (Geosteering Operations Center) and exploration teams were able to pick the formation tops to set the shallow casing point remotely from a few fields. This critical requirement was achieved by using AramcoLink’s Real-­-Time software that collects and transmits surface parameters data.
This Paper will address the important operational aspects that were implemented and demonstrate how this innovative technique has led to improved employee safety and operational cost savings.
Breaking the Implementation Barrier
Authors: Kilgore Laura , Hernandez Margarita , Scott Peter , MacKenzie Kenneth , Whittaker Paula , Vasquez Daniel 
Published: June 2014

Abstract
The barriers for implementing an Intelligent Energy (IE) Solution can vary from asset to asset. To complicate matters further, the challenges are extremely diverse ranging from organizational to technical. Quantifying the challenges requires discovering the gaps between the asset’s current state and the state required for the solution. Leadership commitment, effective workflow modeling, data quality and user’s behavioral change are examples of the kinds of gaps that could result in a delayed or potentially failed implementation.
A key component is to identify the gaps early enough to ensure the asset has the time to allocate resources and close the gaps prior to deploying the solution. The potential exists that once the asset truly understands the time, effort and resources required the business case may no longer justify the implementation for that asset. While this may appear to be a negative it actually results in the ability to improve business decisions.
To ensure a successful IE Solution Deployment and understand the true business value, processes to uncover and address the gaps between the asset’s current state and the state required for the solution is critical. In an effort to tackle the IE Solution implementation challenges, Chevron’s Upstream Workflow Transformation Team has developed processes to identify and address the barriers. These processes have been piloted and adopted as standards for implementing IE Solutions.