bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards Geochemically Accurate Modeling of Carbonate Acidizing with HCl Acid
Authors: Mahrous Mohamed , Sultan Abdullah , Sonnenthal Eric 
Published: October 2017

Abstract
Modeling of wormholing phenomenon is one of the challenging research problems due to the complexity of the process which requires coupling of multi-phase fluid flow, species transport, geochemistry, and geomechanics. There is not a single model that captures all of these aspects of the wormholing phenomenon which requires further development of more accurate 3D multiphase/multiphysics models. This challenge is the principal motive for this work. The objective of this paper is to model carbonate acidizing more accurately from a geochemical point of view. All previous numerical models consider only the acid/rock reaction and the transport of hydrogen ions only. In this work, we also account for chemical reactions between the aqueous species, including the dissolved CO2, under full-speciation transportation. This is done by solving the Reaction-Advection-Diffusion (RAD) equation not only for the Hydrogen ions, but also for all other primary species. Coupling of transport and reaction equations is done using a Sequential Non-Iterative Approach (SNIA). Aqueous kinetics are assumed at equilibrium, while rock/acid reaction is kinetically constrained. Single-phase 2D & 3D simulations of HCl injection in limestone rock are performed under a linear flow geometry. Results of the full speciation simulations are validated with previous experimental work, and compared with results from previous numerical models. This has been accomplished with special focus on the treatment design parameters; optimum injection rate, volume of acid injected to achieve breakthrough. The simulations show that; 1) the full-speciation model captures the different dissolution patterns reported experimentally, 2) confirms the existence of an optimum injection rate that corresponds to minimum volume of acid injected, 3) aqueous kinetics affect the treatment design parameters. We have performed a more geochemically accurate simulation of carbonate acidizing with HCl that takes in to account aqueous kinetics and effect of other species other than hydrogen ions. We believe that this is another step forward towards fully capturing the complex wormholing phenomenon.
On/Off ICD Well Performance Assessment below an ESP Using Intelligent Chemical Inflow Tracer Technology in a Brown Field in Kuwait
Authors: Siddiqui M. A. , Al-Mutairi Moute'a , Mankala R. , Qayyum S. , Prusakov A. , Leung E. , Alabdulwahab M. , Al-Rashidi M. M , Al-Ali A. 
Published: October 2017

Abstract
Kuwait Oil Company is pursuing fast track technology deployment in its fields to meet the strategic target of production. The horizontal wells provide good mean to exploit the reservoir through increased reservoir contact but it brings some inherent problems in optimizing production and low cost well intervention. To address these inherent challenges, the deployment of inflow control device (ICD) has become a normal trend of completion in horizontal wells.
The completion of horizontal wells with ICDs helps in optimizing production but information of inflow contribution from each section qualitatively and quantitatively is still a challenge. In this perspective, KOC has deployed intelligent chemical inflow tracer technology combined with On/Off ICDs below an ESP in a horizontal well located in its northern field to assess the inflow performance of the production. The horizontal well was drilled through a heterogeneous reservoir, which was compartmentalized with swell packers and completed with On/Off ICDs. In these types of wells, traditional production logs are considered risky and expensive due to the limitations of using a small-diameter coil tubing, which must fit through the Y-tool on the ESP. This small diameter coil tubing will go into helical buckling before reaching the toe of the well resulting in an incomplete log for the well. In some cases, the wells are lacking Y-Tool facility, which practically does not allow production logging in the well.
In such cases, the intelligent chemical inflow tracers are used to provide a qualitative assessment of the clean-up phase of production, quantitative inflow information from each zone, and to identify the section producing water along the horizontal well. The use of intelligent tracers overcame the intervention challenges by installing intelligent downhole chemical sensors in pup-joint carriers next to the ICD joints in each compartment from heel to toe to meet monitoring objectives of Kuwait Oil Company. Fluid samples collected from the surface flow lines were analyzed for unique chemical tracer signatures and interpreted the corresponding tracer signals. This has resulted into identification of quality of fluid flowing from each section concomitant with its quantification. In addition, the pilot results have increased the reservoir understanding that leads to optimum ICD designs for future wells in the same reservoir.
This paper discusses the first well installation of its kind in Kuwait, the methodology for selecting the technology, the deployment in the well, and the interpretation of results of water and oil tracers obtained during different monitoring campaigns through fluid sampling.
Improved Method to Evaluate Flowback Additives for Frac Fluids Used in Unconventional Reservoirs
Authors: Himes Ron , Lansford Me Lissa , Snider Jeffrey 
Published: October 2017

Abstract
Productivity of unconventional low permeability sandstone formations and shale plays can be adversely affected by invasion of frac fluid filtrate from hydraulic fracturing treatments. The filtrate can increase water saturation in the pore system when it is not fully recovered upon production of the well decreasing effective permeability. Civan discusses this type of formation damage extensively (Civan 2014).
A number of additives for frac fluid systems have been introduced to aid in filtrate recovery, speed turnaround time and improve production after stimulation. Gravity drainage column tests (GDCT) using ground rock or drill cuttings have been introduced to evaluate these products. The test offers the advantage of rapid evaluation of hydrocarbon displacement of simulated invaded, frac fluid filtrate. However, the test has limitations of pressure and temperature such that it cannot fully evaluate a products ability to displace bound water on the rock surfaces. A flow test method has been developed to improve on the GDCT. The test is conducted at reservoir temperature with elevated pore pressure using either ground formation material or plugs of recovered reservoir core. The test provides a compromise between the need for quick turnaround time for product selection and a more rigorous, time consuming flow study with volume displacement measurements and fluid saturation calculations. Comparison of results from GDCT and the new method are given.
Field Study: Embedded Discrete Fracture Modeling with Artificial Intelligence in Permian Basin for Shale Formation
Authors: Du Song , Liang Baosheng , Yuanbo Lin 
Published: October 2017

Abstract
Even with the current low oil price environment, oil and gas production from shale formations becomes increasingly important. The drilling and exploration activities in the Permian Basin are the most active unconventional play in the U.S. Therefore, engineers need effective and efficient full field planning and development strategies for an economically successful project. Since in the coming years, thousands of horizontal well drilling activities are expected, field planning, such as the well landing design, spacing study, and operational sequence, could have huge impacts on economic field development. Full field models using unstructured grids can capture detailed geometry information like fracture distribution. It is, however, computationally expensive and often numerically unstable (convergence issues). We investigated the embedded discrete fracture modeling (EDFM) with artificial intelligence (AI) to overcome challenges associated with the unstructured modeling.
We applied the concept of EDFM, in which a fracture is embedded in the structured matrix grid that does not conform to the discrete fractures. EDFM uses relatively low matrix resolution but honors fracture geometry and connectivity: fracture orientation, shapes, and intersections. As a result, the flow behavior in fractures is well preserved. Furthermore, EDFM has a large advantage of computational efficiency, compared to unstructured full-field models. We also proposed to employ AI techniques to optimize the hydraulic fracture networks by identifying the most important fracture geometries and eliminating the unpropped structures. Our study combines EDFM and AI techniques to make numerous full field simulation runs making the uncertainty analysis affordable for better planning decisions.
In this study, we verified the effectiveness and efficiency of EDFM and AI techniques with various models. Then we applied the technique for a full field well interference study to guide the development sequence. In the full-field Permian Basin case study, the new method accurately captured the influence among four neighboring horizontal wells. The results are very close to the reference solution from full field unstructured simulations, but with a huge improvement in efficiency.
Look Ahead Geosteering via Real Time Integration of Logging While Drilling Measurements with Surface Seismic
Authors: Arata F. , Mele M. , Tarchiani C. , Tosi G. , Chinellato F. , Nickel M. , Athmer W. , Salim D. C. , Dahl G. V. 
Published: October 2017

Abstract
Structural estimation capability ahead of the bit is evolving with innovative combination while drilling of borehole and surface data in real time. A pioneering workflow has been developed to recalibrate the reservoir structure via integration of surface seismic with synthetic seismic, derived from logging-while-drilling (LWD) measurements.
Modern LWD services have nowadays reached a significant depth of investigation capability, expanding the horizons of geosteering applications. The most recent ultradeep azimuthal electromagnetic (EM) technology provides real time information on a cylinder of rock around the wellbore, up to 200 feet of diameter. This technology enables a new opportunity to update the pre-drill 3D geo-model with the measured local volume of information. Synthetic seismic, derived from EM measurements, is compared with real seismic data, using non-rigid matching to quantify the depth mismatch. The estimated displacement is then applied to the real seismic and to the pre-drill 3D geo-model repository (i.e. identified reservoir horizons, faults, and geobodies) to predict the structural setting of the reservoir ahead of the bit. It is possible to iterate through these steps using an automated process while geosteering.
The workflow was tested on post-drill data acquired on an Eni well, recently geosteered within an oil reservoir consisting of fluvial and deltaic deposits of Triassic age. The automated interpretation tools, integrated on the seismic interpretation software, allowed building a pre-drill model in two-week time. The model provided a base for the creation of the geosteering roadmap considering the structural features potentially present along the planned trajectory. The real time simulation lasted two days in a play back mode, focusing on the assessment and validation of the workflow. Each process iteration took few minutes to provide results, validated in parallel with LWD available data. The calibration provided a robust dip and structure estimation and additionally the confirmation of fluid contact position, as identified in the pre-drill model.
The workflow unlocked extra look ahead possibilities for optimal geosteering, and proved to be able to provide robust information 150m, on average, ahead of the bit. The presence of structural discontinuities was successfully validated within 30 m measured depth from the predicted position. This novel approach is a step further toward the possibility of providing accurate reservoir updates ahead of the bit, and so forth to improve well placement operations while updating 3D geo-models in real time.
Implementation of ESPCP Technology to Decrease Well Intervention Index in Casabe Field
Authors: Bahamon Cristhian C. , Hill Carlos Reyes , Sanita Carlos , Artola Ricardo , Lapania Fernando , Doval Jorge 
Published: October 2017

Abstract
The development plan of Casabe field defined the drilling of producer wells with "S type" deviation geometry and cased hole completion with progressive cavity pump (PCP) systems because this plan offers the greatest advantages in wells with solids production. However, this combination creates an environment for repetitive failures due to severe friction between rod string and production tubing. A group of 40 wells with PCP was identified;these wells had three or more interventions per year. An extensive root cause analysis concluded that 44% of failures in wells with PCP were directly linked to tubing and rod wear, especially in highly deviated wells and high operating revoluetions per minute (RPM).
With the aim to increase the run life and decrease the intervention index of producer wells, a pilot test of new technologies such as the electric submersible PCP (ESPCP) were proposed; an ESPCP isa bottom-drive PCP that eliminates the rod string while maintaining the advantages of solids handling. These capabilities were expected to contribute to a significant increase in run life and, thus, have a direct impact on operating costs and production.
The first stage of a pilot test started in August 2012 with the installation of the ESPCP system in three wells. The results showed an outstanding increase of run life and savings of USD 3.6 million. By the end of 2016, 10 wells were producing with this system. This paper describes the implementation of the ESPCP system in Casabe field, the technical and economic advantages, and the lessons learnt.
Solid State Gyro While Drilling Technology Provides Accuracy And Robustness
Authors: Lowdon R. , Igarashi Juei , Sargin Doruk 
Published: October 2017

Abstract
Increasingly crowded field, platforms and pads combined with tighter well spacing have led to an increase in the need for gyroscopic measurement systems that are not affected by the mass of steel surrounding them. Gyroscopic surveying tools have evolved from photomechanical to while drilling spinning mass technologies. This paper will highlight a new sophisticated but rugged type of gyro surveying system derived from solid state sensing technology. It will provide case studies as to the novel gyro systems accuracy when compared to other survey technologies such as conventional gyro or magnetic surveys.
Magnetic surveys accurately measure magnetism, they cannot however differentiate between the Earth's magnetic field and offset casing or other external magnetic sources. This means gyro technology is sometimes essential to safely and efficiently drill congested fields. The new gyro technology has been run in a large number of wells where it can be directly compared to either other gyro systems or magnetic surveys. All inclination and azimuth attitudes have been covered, with latitudes varying from the North Sea to central Asia. The solid state gyro system has been compared to all survey measurements in each of these wells. These comparisons will include analytics of positioning difference between surveying systems in both discreet and cumulative well placement terms.
The breadth and number of runs conducted with this new solid state gyro have shown that its accuracy is at least comparable if not superior to most current gyro technologies, while offering some considerable advantages. The gyro tools short survey cycle means multiple surveys are taken during one connection. This allows for trapped torque or pipe movement issues with the concurrent potential to reduce surveying time on a rig. This solid state gyro is non mechanical and robust requiring minimal calibration allowing for tools to be run from one job to the next without the need for tool returning to a calibration facility.
Rotating mass gyros have been the industry backbone for the last fifty years with important but evolutionary steps in terms of accuracy and robustness. Solid state gyros are far more robust while offering at least the same level of accuracy which is a step change for an industry that requires continuing increases in survey accuracy and wellbore positional assurance. The accuracy of other solid state systems which have been developed for mass market non-oil industry applications like smart phones has been limited. This solid state gyro system's unique gyro compassing methods have solved that problem, producing industry leading accuracy with the ruggedness required to last in the downhole environment.
The Role of Elasto-Plasticity in Cavity Shape and Sand Production in Oil and Gas Wells
Authors: Wang Haotian , Sharma Mukul M. 
Published: October 2017

Abstract
Previous experimental observations have shown the formation of distinct failure patterns and cavity shapes under different stress and flow conditions. With isotropic stress, spiral failure patterns with localized shear bands are likely to form. On the other hand, under anisotropic stress, V-shape cavities, dog-ear cavities or slit mode cavities are usually observed. However, the mechanisms for the development of these sanding cavities remain unclear. In addition, in order to accurately predict the onset of sanding and predict the sand production rate, it is crucial to capture the physics of formation of these cavities during sand production.
This paper presents a fully coupled poro-elasto-plastic, 3-D sand production model for sand production prediction around open-hole and perforated wellbores in a weakly consolidated formation. Sanding criteria are based on a combination of shear failure, tensile failure and compressive failure from Mohr-Coulomb theory and strain-hardening/softening. Once the failure criteria are met, an algorithm for entrainment of the sand based on the calculation of hydrodynamic forces is implemented to predict sand erosion and transport. Dynamic mesh refinement has been implemented to effectively capture the strain localization regions.
The model has been validated with multiple analytical solutions. In addition, it is applied to compare with previous sand production experiments that have explored the different cavity shapes formed under different conditions. The model is capable of not only explaining the mechanisms responsible for each type of cavity shape but also predicting what cavity shape will be formed under a specific set of conditions. Parametric studies for these cases provide additional insight into the important role that the post-yield, poro-elasto-plastic properties of the sand play in controlling the sanding mechanisms and cavity development. This allows us to much more accurately predict the onset of sanding and the sanding rate.
Lessons Learned from Evaluation of Frac-Pack Flow Performance Before and After Full Clean-Up for Subsea Wells in High-Permeability Gas Reservoirs
Authors: Nozaki M. , Burton R. C. , Pandey V. J. , Furui K. 
Published: October 2017

Abstract
The objectives of this paper are: 1) to evaluate clean-up flow effects on High Rate Water Pack (HRWP) and Cased Hole Frac Pack (CHFP) completions and 2) to develop predictive models to quantify clean-up effects on well inflow performance in these types of sand control completions.
Analysis methods include: data acquisition and well test design for reservoir property estimation, multi-rate test and non-Darcy skin factor analysis, and perforation tunnel permeability factor (Kpt/Kr) analysis to evaluate gravel pack flow performance. Eight zones from five gas wells have been investigated using this procedure. All pressure data were obtained by intelligent well systems’ (IWS) permanent downhole pressure gauges located at reservoir depth.
The study results show a two-fold improvement in the average perforation tunnel permeability after clean-up flow. Based upon the study findings, two empirical correlations that can predict postclean-up well inflow performance are developed. For planning purposes, Kpt/Kr improvement factors can be estimated based on formation permeability while for wells tested using short-term clean-up flows Kpt/Kr improvement factors and stabilized well flow potential can be calculated from Water/Gas Ratio (WGR) data collected during the clean-up flow period. These predictive models are expected to help engineers assess future well performance for high-rate water pack and frac-pack completions in high permeability reservoirs.
A thorough review and comparative well performance analysis of a series of HRWP and CHFP wells has been conducted using high quality downhole pressure data. The perforation tunnel permeability (Kpt/Kr) database and correlations presented in this work can be used for predicting both initial and long-term well flow performance of gravel and frac-packed wells, which can be very useful information for optimizing future completion designs and field development plans.
Testing Tutorial-Lecture Swapping Technique in Reservoir Engineering Course to Enhance Students’ Learning Experience
Authors: Hussain Furqan , Neal Peter 
Published: October 2017

Abstract
In the period 2008 to 2016, average enrolments in courses offered by the UNSW School of Petroleum Engineering have grown from approximately 40 students to more than 100. This has rapid growth has created challenges for the School as the numbers of teaching staff has lagged behind the number of students. In order to ensure our students continue to enjoy a high quality learning experience across the program, we tested innovative teaching techniques in our 3rd year Reservoir Engineering course. In this paper we discuss some reservoir engineering example to explain our improved teaching techniques.
Students in this course are assumed to have a sound grasp of the fundamental concepts of transport in porous media. Therefore, new content was introduced in the tutorials before the lectures. This swapping of the traditional order, requires students to actively apply existing knowledge to new environments and enables students to collaboratively construct knowledge of the course content in a problem-solving context. A key advantage of this approach is that we can ensure that students are able to see the real-world importance of what they are learning as it is being taught. Further, students can identify incorrect approaches to solving the problems at the same time as they are being introduced to new concepts which can be challenging in conventional flipped classroom approaches. We used a number of feedback approaches to measure the success of our techniques.
Feedback from academic colleagues and our students is encouraging. We have found that 85% of students who completed the anonymous surveys are satisfied with tutorial-lecture swapping. The tutorial problems must be designed in a way that the students have prior knowledge to understand the problem statement. Therefore, this approach might only be applied for advanced engineering courses. This technique can be used for other advanced level Petroleum Engineering courses as well.