bluuebunny/crossref_metadata_2025 huggingface dataset:
Demonstration of Processing Capacity Enhancement on an Offshore Facility through Systematic Field Trials
Authors: Rodrigues Neil , Joshi Nikhil , Jagneaux Ricky L. , Kapadia Kashyap P.
Published: October 2017

The Constitution Spar is located in Green Canyon block 680 in the Gulf of Mexico, approximately 190 miles from New Orleans and in approximately 5,100 feet of water. The original nameplate separation capacity for the spar is 70,000 BOPD and 200 MMSCFD and production potential from future developments is expected to exceed this limit. In order to maximize the value to Anadarko and its partners, a systematic effort is underway to enhance the throughput of the facility.

The methodology includes evaluating all components of the subsea and topsides system for potential bottlenecks and identifying actions to remediate them. The overall goal is to utilize existing infrastructure to maximize production volumes with minimal investment into facility upgrades. One of the bottlenecks that was identified was the design capacity of the production separators. Separator designs are typically performed with little information on reservoir fluids and separation correlations do not always match field performance data. There is also very limited information available in the literature about improving separation efficiency in the field. Therefore, field tests were performed with the goals of identifying any deficiencies that would inhibit the facility from reaching nameplate capacity, as well as to identify areas of improvement that would allow the facility to processbeyond this limit.

The test as a whole was successful and the first and second production trains saw capacity increases of 23% and 32% respectively. All the separation Key Performance Indicators (KPIs) that were established prior to the test were met or exceeded due to rigorous management of the process conditions and chemical treatments.

In addition to the test results, the paper will include discussion on pre-planning, safety review, test design and real-time performance tracking, all of which were critical in order to ensure that the test objectives were met with minimal impact to facility uptime. There will also be discussion on specific separation challenges that were faced and actions taken to address them.
Dry Liquids on Silica as Secondary Emulsifiers for Drilling Mud Applications
Authors: Lifton V. , Gorka J. , Parrish D. , Davidson J.
Published: October 2017

This paper presents a systematic study of the performance of a family of "dry liquid" emulsifiers prepared via a novel "liquid-to-powder" process based on absorption of liquid by special types of synthetic amorphous silicas. The ability to use chemicals in solid form improves safety, handling, and ease of use. This process also avoids complications stemming from possible spills when using liquids, and the challenges of maintaining particular concentrations of the components normally affected by solvent evaporation.

Secondary emulsifiers are used in oil-based drilling fluids to enhance the performance of primary emulsifiers used to create a water-in-oil emulsion. In their native state these emulsifiers are high viscosity and high pour point liquids, which are normally difficult to dispense, especially in a cold environment. Secondary emulsifiers derived from canola fatty acid were investigated in this project and by using synthetic silica they were converted into "dry liquids". Silica used in the study were prepared by the precipitation process, with the structure required to absorb large volumes of liquids, immobilizing them in the internal pore volume in the typical weight ratio of 2:1 liquid-to-silica. The resulting freely-flowing powder can then be used "as is", and is not affected by the temperature or moisture in the environment.

The viscosity data shows that the "dry liquid" secondary emulsifier has performance equal to the "standard"liquid secondary emulsifier with no negative effects. The emulsion stability data suggests that the dry liquid secondary emulsifier maintains good electrical stability of the drilling mud. Overall, the data show that the secondary emulsifier has the same functionality in its natural liquid form and in the "dry liquid" form on silica carrier.

"Liquid-to-powder" method is a useful approach of converting challenging materials such as hygroscopic solids, viscous and freezable liquids into free-flowing powders for precise dosing and ease of handling. It expands the ability to create "dry" formulations based on the individual components absorbed onto inert silica carriers.
Seismic Inversion Based SRV and Reserves Estimation for Shale Plays
Authors: Sinha Saurabh , Marfurt Kurt J. , Devegowda Deepak , Pires de Lima Rafael , Verma Sumit
Published: October 2017

Estimation of stimulated rock volume (SRV) is the cornerstone offield development planning in shale reservoirs. The EUR has a first order dependency on the SRV and therefore its estimation is extremely critical for field development.

In this paper, we propose a methodology to estimate the SRV and hence the EUR for a shale reservoir using seismic data, flow and geomechanical simulation. The backbone of our methodology is seismic inversion coupled with geomechanical simulation. We apply our technique to data acquired from the Barnett shale.

In this work, we first use 3D seismic and sonic logs to perform pre-stack seismic inversion. Then, we derive the distribution of Poisson's ratio and Young's modulus in the area of interest (AOI). We constrain the porosity in our geo cellular model using a rock type model. Our rock type model for this work is based on k-means clustering on multi-well log analysis.

We modeled a well in the AOI for which microseismic data is available. Weused a coupledflow and geomechanical simulator to mimic the fracturing process and the fluid volumes injected during the actual completion of the well. For geomechanical coupling, we used Barton-Bandis model in seismic inversion-derived Young's modulus and Poisson's ratio 3D volumes. Next, we compare our results with the SRV obtained by an analysis of microseismic data. We reconcile differences in the model-derived SRV and then calibrate the resulting flow model and use the history-matched model for forecasting production.

Our results indicate an excellent match on SRV and therefore production data. Because we usevariable geomechanical parameters along the lateral, we observe irregular SRV's and drainage areas consistent with the microseismic data. Our methodology for predicting microseismic can be used for asset evaluation, acreage prioritization and to optimize the completion design in unconventional plays.
Innovations in Engineering Graduate Course Delivery for Oil and Gas Professionals
Authors: Goulis Kelly , Ershaghi Iraj
Published: October 2017

In today's exponentially changing technological landscape, the upgrading of skills and knowledge is of critical importance. Like in other professional fields, engineers, working in the oil and gas industry also need to pursue advanced degrees and to keep their skills up to date. For anyone working in the petroleum industry, partly because of the remote location of operations and in part because of frequent travel-associated assignments, the environment for pursuing advanced degrees may seem restrictive and impossible. Also, the nature of the oil and gas industry often requires professionals to work in locations away from major cities; often travel to remote locations and be away from their offices for a substantial period. This can be discouraging and make it impossible for these professionals to enroll in traditional on-campus educational degree programs. More importantly, even if located near a major metropolitan area, there may not be a credible or relevant local university program to provide the necessary education nor is there expectation to teach such graduate courses. Indeed, the desire to enhance professional qualifications and to acquire graduate education can rapidly diminish when there is limited access to the accredited educational providers. Added to that is a fear for getting involved but later facing roadblock in balancing work, family responsibilities and the intended educational program.

In recent years, an effective way to circumvent this obstacle has been relying on modern communication methods that enable access to accredited advanced education via high-quality Internet to the classroom regardless of individual's location. This breakthrough has provided a unique continuous learning opportunity for many engineering or science graduates in oil and gas professions and at various stages of their careers. But experience shows that the course delivery besides video communication needs other components to provide an inviting, effective and appealing virtual learning environment. We share experiences gained at the DEN@Viterbi system that has included many conveniences to the part time students1.
Aggressive Fracturing Treatments in Horizontal Wells: Benefits and Pitfalls
Authors: Daneshy Ali
Published: October 2017

The oil and gas industry has been successful in its use of trial-and-error as the main technique for enhancing the productivity of fracturing treatments in horizontal wells. The lower fracturing costs of the last three years have provided the impetus for moving in the direction of more aggressive treatments; much larger volumes of fluid and proppant, longer horizontal reaches and shorter spacing between adjacent fractures. In general, these changes are claimed to have improved the productivity of fractured horizontal wells, at least in the short term for which data has been available.

The justification for these changes requires assuming a different model of fracture propagation than is often assumed by the fracturing community. Closer examination of these treatments indicates that they implicitly assume a more planar fracture shape. Some of the existing data on pressure interaction between offset wells while fracturing shows incidents of fracture shadowing as well as frac/frac intersections. At times the observed data indicates low effective fracture conductivities, which is in-line with the practice of using more proppant. The relatively consistent fracture orientation within a single well and in multiple offset wells indicates larger difference between the two horizontal principal stresses than usually assumed within the fracturing technical community. This condition is needed for the success of the more aggressive treatments.

On the negative side, aggressive well and fracture spacing can increase fracture length and the likelihood of interference between fractures in adjacent wells. Taken too far, this can have significant impact on future reservoir development, including damaging the existing fractures, and production re-distribution between offset wells.
Collaborative Work Environment Implementation Strategy for Marginal Field Operators
Authors: Udofia Emmanuel , Obong Benjamin , Rui Ray Zhenhua
Published: October 2017

Collaborative Work Environment (CWE) is an operation integration concept supported by real-time systems (tools and facility), defined business processes and the right set of domain experts. The objectives in Collaborative Work Environment implementation includes; providing an operating asset the benefits of real-time operation optimisation and reduction in personnel unsafe travel exposure alongside effective team collaboration resulting in faster decision making using the intelligent oilfield capabilities. This paper assesses, hypothetically, the Collaborative Work Environment implementation strategy for a marginal field operator in Gulf of Guinea.

Collaborative Work Environment solutions are not really new to the oil and gas industry, as it has been widely implemented and embedded by major oil and gas companies in different regions around the world. However, what that is really novel are the challenges of implementation by marginal field operators. The challenges in implementing Collaborative Work Environment by marginal field operators includes; high-cost relative to the asset financial base and importantly the need for ‘visible’ benefit of intelligent oil field solutions linked to the business objective of the small operator. This paper aims to highlight an effective business strategy of implementing intelligent oil field by a marginal field operator by using procedure of comparing a case study during a well workover operation against standard implementation strategy by the major oil and gas companies.

The benefits of the Collaborative Work Environment were clearly ‘visible’ leveraging on the real-time support from the office to the field using the Collaborative Work Environment technology, facility and processes. The immediate ‘visible’ benefit of Collaborative Work Environment strategy during the well intervention operation included; faster team decision-making and situational awareness collaboration with remote location using intelligent oil field capabilities.

This experience provided a novel platform for developing an asset-specific intelligent oil field implementation and embedment strategy for the marginal field or small exploration and production operators in environment similar to the Gulf of Guinea. The recommendations from this paper will form a quick reference tool and assist in developing Collaborative Work Environment implementation and embedment strategy for small oil and gas field operators globally.
Circulation Subs and Their Impact on Downhole Hydraulics
Authors: Liu Gefei , McCormick John
Published: October 2017

Circulation subs are downhole tools designed to create an additional flowpath from the pipe to the annulus. The percentage of fluid that exits the string instead of traveling down to the bit or shoe depends not only on the size of the circulation sub ports, but also upon the density and rheology of the fluid, the flow rate, and the sub's position in the string.

This paper takes a thorough look at the variables that affect the percentage of fluid travelling the two flowpaths when using a circulation sub, along with their impact on pump pressure and equivalent circulating density (ECD). A description of the various common operations and uses of circulation subs are also discussed. The flow rate, circulation sub's position in the string, fluid density, fluid rheology, and total flow area out of the circulating sub were analyzed to determine the degree of flow split, pump pressure, and ECD changes.

Graphical representations of outputs are presented to illustrate the results of changing variables using circulating subs. The sensitivity of the flow split between fluid traveling down the string vs. into the annulus when the total flow area, depth of the circulation sub, flow rate, fluid viscosity, and density are discussed. These variables are also used to evaluate the impact on each other, with a focus on the resulting pump pressure and bottom hole ECD.

This paper seeks to disseminate information on the impact of an available tool on common downhole operations, variables which need to be understood to properly plan for these tools, and the appropriate methods for modeling using computer aided numerical analysis.
Adaptive Real-Time Machine Learning-Based Alarm System for Influx and Loss Detection
Authors: Unrau S. , Torrione P.
Published: October 2017

Unexpected influxes and losses pose a significant risk to rig personnel, the environment, and drilling efficiency. Influxes and losses typically manifest in the circulation system (e.g., as increases or decreases in flow and mud-volume) and other rig surface measurements. Automated, real-time interpretation of these drilling parameter traces is complicated by the highly variable and transient nature of the circulation system during normal drilling operations. As a result, the most commonly deployed automated alarm systems (e.g., fixed +/- bounds) have high false alarm rates, and are sometimes treated as unreliable by rig personnel. Recent advances in machine learning enable data-driven algorithms to identify anomalous behavior in real-time data traces, but until recently, the uptake of these algorithms has been hindered by driller's lack of trust in these automated systems, and the complexity of explaining why these so-called "intelligent" algorithms do (or don't) generate alarms in any given scenario. This paper documents a novel machine-learning algorithm framework for circulation system monitoring that was designed to maintain a very low false-alarm rate and earn the driller's trust by explicitly providing expected safe operating bounds on flow-out and pit-volume, so that even during long (e.g., 24-hour) periods without alarms, the driller knows that the system is operational and trustworthy. We present performance results generated across a massive body of drilling data that illustrate the trade-offs between detection rate and false alarm rate that are inherent to any machine learning (indeed, any algorithm) approach to event detection, and show how explicit bound generation can be used to improve driller trust and acceptance.
A Statistical Mechanics Model for PVT Behavior in Nanopores
Authors: Coskuner Y. B. , Yin X. , Ozkan E.
Published: October 2017

Recent studies on phase behavior in nanopore confinement reveal inconsistent and contradicting results about the shift of the phase diagram and critical point. This paper focuses on statistical mechanics and molecular simulation to model the PVT behavior in confinement. Grand Canonical Monte-Carlo simulation is used to observe the effect of confinement on phase behavior of pure methane in 2 nm. The model takes into consideration the effects of the intermolecular forces between fluid particles and between fluid particles and solid surface. Density of methane is obtained from simulations at different pressures under isothermal conditions to determine the phase transition point. Results are compared with the published studies and the differences are discussed. It is shown that the size of the simulation box significantly affects the results of molecular simulation. As a result, some of the conclusions drawn in the literature about the shift of the critical point are questioned.
Towards Geochemically Accurate Modeling of Carbonate Acidizing with HCl Acid
Authors: Mahrous Mohamed , Sultan Abdullah , Sonnenthal Eric
Published: October 2017

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

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

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

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

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

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

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

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

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

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.
Integrating Human Factors into Petroleum Engineering's Curriculum: Essential Training for Students
Authors: Dadmohammadi Y. , Salehi S. , Kiran R. , Jeon J. , Kang Z. , Cokely E. T. , Ybarra V.
Published: October 2017

The contribution of Human Factors, in complex commercial and contractual environments like the oil and gas industry, is fully-fledged and admitted. With the understanding that there were cascading failures due to human errors, the root cause analysis of accidents reveals that many of them were preventable. The Human Factors has not been accentuated thoroughly in this industry, and, traditionally, the focus has been on personnel knowledge and competence. In addition, lack of emphasis on Human Factors in academia as a backbone of the industry could be another reason for this negligence. Therefore, the proper academic training, which thoroughly emphasizes the non-technical skills (NTSs) in conjunction with Human Factors, is lacking in the curriculum of complex engineering programs like petroleum.

For the first time, at the University of Oklahoma, the Human Factors in Oil and Gas Operations class was offered. The offered course fulfilled the mission of training petroleum engineering students to make an impact on oil and gas industry. In this class, the students were introduced to the required NTSs in the drilling operation. The course content was designed to include technical concepts in drilling such as well barriers' philosophy, challenges in well flow control, plugging and abandonment operation, and kick detection. Also, several NTSs include effective communication, decision-making, situational awareness, teamwork, individual and group scenarios based well control training. The course content reassures that young professionals gain applicable NTSs and carry them to their work environment asserting safe and environmentally sustainable operations. A novel training approach was offered to integrate the theories of Human Factors with NTSs through the virtual reality simulation experience. The state-of-the-art Virtual Reality Drilling Simulator (VRDS) facility coupled with a commercial drilling simulation software to facilitate the scenario-based training for students.
Novel Techniques and Completions for the Abandonment of Horizontal Wells
Authors: Mali Gwyn A. , Clark Travis M. , Barrett Mark A. , Tran Nhuan Quang
Published: October 2017

Horizontal wells are a regular feature of many oil and gas fields and pose different challenges to their vertical counterparts for the entire well life-cycle. A regularly overlooked element during well completion design is the preparation for ease of abandonment. Horizontal wells are often completed with slotted liners/gravel packs and in a toe-up configuration, and if required, the abandonment of these production sections can be a risky operation using standard abandonment tools and techniques.

This paper describes the execution and lessons learned of several horizontal well abandonment operations, including a novel abandonment procedure that overcomes many of the limitations of conventional abandonment procedures in the toe-up horizontal configuration. This novel technique involves the installation of tubing in the horizontal slotted liner, placing cement along the horizontal liner from the tip of the toe via an initial circulation operation, then subsequent perforation and packer squeeze operations to remediate any gaps in cement isolation.

The paper also shares the details of a recent completion design change implemented on several horizontal wells with slotted liners to enable simpler abandonments in the future. The completion change involves the installation of a series of blank pipe sections with swellable packers along the horizontal liner section. These sections will be used in the future to enable simple low-cost and effective cement squeeze procedures with coiled tubing units utilizing cement retainers or packers.

The novel procedure and completion changes described have become a new toolset for the safe and efficient abandonment of toe-up horizontal wells.
Quantification of Transportation of Deformable Gel Particles in Porous Media
Authors: Jing Wang , Hongling Zhang , Huiqing Liu , Wei Zhao , Haomin Liu , Chuanjin Yao , Jiapeng Zheng , Yinghao Shen
Published: October 2017

Channeling is a ticklish problem of water-flooding in mature reservoirs. Deep fluid diversion (DFD) using deformable gel particle (DGP) has shown promising conformance control and improvement of sweep efficiency for enhancing oil recovery. The transport behaviors of DGP including shearing, plugging, deformation, and breakage are significantly complicated. It is extremely different from percolation of fluid and sand-removal problems. Although some empirical models or knowledge have been reported in literature, there have been few quantitative investigations or mechanistic interpretations to such behaviors. Without a good understanding of these behaviors, reliable modeling and optimization of DGP treatment would be impossible. Therefore, quantification of DGP transport behaviors in porous media is extremely essential. In this paper, we first conducted a set of experiments to measure the characteristics of DGP passing through and the breakage using variable-diameter capillary. Then, the corresponding derivation of DGP passing through the throat was demonstrated based on the elastic mechanics theory. After that, experiments of DGPs transport in porous media were conducted to study the shearing behavior and plugging capacity for different scenarios. Finally, the oil displacement experiments of parallel sand cores with different permeabilities and viscosities were carried out using different DGPs to validate and apply the above quantitative achievements. The results show that the pressure gradient for DGP passing through exponentially increases as the diameter ratio of DGP to throat. It is also a function of elastic modulus, Poisson's ratio, the diameter ratio of DGP to throat, and friction coefficient according to the derivation. Moreover, the derived model has a good agreement with the experimental results. There is a critical diameter ratio of DGP to throat, above which the DGP will break under an enough pressure. Both resistance factor and sheared DGP diameter are the function of flow rate, the diameter ratio of DGP to throat, and initial diameter. The above models can be used to choose optimal DGP size and injection parameters for a certain scenario. The experimental results of oil displacement support the quantitative achievements very well. This work provides a solid mechanistic theory for modeling DGP flooding and offers a useful guidance to the design of DGP flooding in field applications.