bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Low-Density Direct Emulsion (DE) System has been Successfully Formulated for Mature Depleted Fields
Authors: Collins Natalia , Chumakov Evgenii 
Published: January 2016

Abstract
A low-density direct emulsion (DE) system has been successfully formulated to minimize formation damage in mature depleted fields.
Key objectives for the DE system are to provide all the functions of traditional reservoir drill in fluids (RDF) in terms of efficient cutting suspension and carrying characteristics, effective fluid loss control and friction coefficient, while minimizing overbalance on depleted formations. Excessive overbalance on the formation would potentially cause severe losses and could result in formation damage, with negative impacts on the environment, and an increase in overall fluid cost. This novel oil-in-water DE system consists of a dispersion with oil as the internal phase, and water as the external phase. It targets densities less than 8.17 lb/gal to minimize overbalance on the formation while providing all the benefits of an emulsion system – enhanced friction reduction, effective fluid-loss control, superior rheology for hole cleaning and minimal ECD, and effective clay inhibition.
Numerous attempts of using DE systems in oil field drilling fluids have been made in the past. However, DE systems have never been fully accepted in industry due to difficulties maintaining the emulsion stability and its sensitivity to common contaminants. A novel thermodynamically stable DE system has been successfully formulated and used to drill a well with no excessive losses or emulsion stability issues.
The paper will present a detailed study of the laboratory development of the DE system along with field application data and lessons learned.
Invasion and Movement of Fluids in Shale Formations and Wellbore Stability
Authors: He Wenwu , Jimbi Esmeraldo , Chamberlin Molly , Zakaria Ahmed 
Published: January 2016

Abstract
The invasion and movement of drilling fluids through shale formations can significantly contribute to wellbore instability. By combining the experimental results with the microstructural studies of core samples, we will examine the invasion and movement of fluids in shale formations near wellbore, including the mechanisms, rates, affecting factors, and impact on shale stability.
Pre-test core studies provided insight into rock composition, structure, fracture distribution, water activity, and pore-fluid composition. Pore-fluid transmission tests were conducted on preserved shale cores from four different formations, each with a different water activity measurement. Thin section analyses of post-test cores were conducted to evaluate shale-fluid interactions and the impact of fluid invasion and movement on shale stability.
Test results show clear evidence of a reverse osmosis process out of the shale. The reverse osmosis increased when the difference between the water activity of the shale's pore fluid and the drilling fluid also increased. A water activity difference of &gt;0.07, and the resulting pore-pressure drop (caused by the reverse osmosis), can subdue the impact of fluid invasion from drilling fluid to formation and led to a net decrease in downstream pressure. Reverse osmosis could cause downstream pressure below the initial value in a few minutes. A pore-pressure drop due to reverse osmosis may improve the stability of wellbore due to an increase in effective drilling fluid support. However, tests show that strong reverse osmosis could cause fracturing from over-dehydration of the shale. Tests also indicate that invasion along fractures increases pore pressure, even with a potential for strong reverse osmosis. Adjusting the water activity of drilling fluids to closely match that of the shale formations while minimizing fluid invasion along fractures and other fluid channels reduces wellbore instability.
Engineered Solutions to Address Deepwater Remedial Cementing Challenges
Authors: Fuller George A. , Mercado Steven , Mead Christopher 
Published: January 2016

Abstract
Performing cementations in a deepwater environment poses many unique challenges during the drilling and completion operational phases in the Gulf of Mexico. These challenges add further difficulty and risk to an already complex operation.
During the course of constructing the wellbore, it may be necessary to perform un-scheduled remedial cementing operations to acheive the main objectives. Squeeze cementing performed to remediate undesireable well conditions which may have resulted during the drilling phase (major mud losses) or as a result of a poor primary cement job (insufficient zonal isolation) must be thoroughly analyzed during planning to understand all the critical parameters needed to execute the right plan.
When designing for a squeeze job, key decision factors during the planning process must be addressed for a successful outcome. The success or failure of a squeeze cement operation relies on 1) understanding what is the objective of the squeeze operation 2) determination of the optimum cement placement depth, 3) development of an effective placement procedure with proper technique and down-hole tools employed, 4) proper design of cementing fluids including washes and spacers, 5) flawless execution with a detailed pressure/rate/volume record of fluid injection, and 6) a meaningful post evaluation of the squeeze operation’s results to determine if objective was met.
This paper will provide guidance on addressing the key decision factors, development of a proper placement strategy, general design guidelines for appropriate cementing fluids to employ, and how to evaluate if the objective was met. Results will be presented from recent deepwater case histories to demonstrate the successful application of this methodology for squeeze jobs and the techniques used.
Vibration Monitoring and Mitigation - An Integrated Measurement System
Authors: Greenwood Jeremy A. 
Published: January 2016

Abstract
Dynamic dysfunctions of the drillstring are extremely complex to model, and it is difficult to produce timely model updates to keep up with the continually changing conditions during drilling operations. This paper describes an integrated measurement system that mitigates the effects of damaging downhole vibration and enables the driller to instantaneously respond and evaluate the effectiveness of corrective actions.
The failure to measure all of the correct parameters will leave the driller blind to the existence of damaging vibration and lead to sub-optimal performance or equipment and drillstring failures. The integrated system of downhole and surface measurements combines a significant amount of surface, downhole, and formation information to help the driller to correctly identify the vibration mechanism and to determine the appropriate response. The system measures the movement of the bottomhole assembly (BHA), the levels of energy generated during episodes of vibration, and the energy going into the system.
The capability to clearly and concisely present the results of the analyses to the driller and to produce recommendations for the correct mitigation strategy is a powerful tool for controlling downhole vibration. Monitoring surface weight on bit (WOB), torque (TRQ), rotary speed (RPM), and standpipe pressure (SPP), and performing a frequency analysis helps to identify vibration signatures for stick/slip and bit bounce. Mechanical specific energy (MSE) calculations determine drilling efficiency. Downhole accelerometer, gyroscope, magnetometer, bending, tension, and torsion measurements used alongside formation evaluation data identify bit bounce, bit whirl, BHA whirl (both forward and backward), torsional resonance, bit chatter, modal coupling, and lateral shocks. A three-tier warning system brings attention to the presence of vibration, supplies the mechanism and corrective actions, and provides detailed analytical information to the expert. Tracking environmental exposure of downhole equipment enables the driller to determine when the operating limits of WOB, RPM, temperature, and dogleg severity (DLS), as well as axial, lateral, and torsional vibration, are being approached or exceeded.
This smart system reduces the reliance on expert analysis to identify the correct actions to mitigate the problem, leading to an increased speed of response. The combined capacities of identifying all vibration mechanisms, tracking the environmental exposure, and representing this information in an easily understood manner provides a powerful tool for the control of drilling operations.
Iron Roughneck Make Up Torque–Its Not What You Think!
Authors: Zenero Nathan , Koneti Srinivasa , Schnieder Warren 
Published: January 2016

Abstract
Declining marginal profits demand that operating companies and drilling contractors review their practices and examine ways to optimize processes and reduce unplanned expenditures. One area that has been largely overlooked is iron roughneck make up torque. Until recently, most iron roughnecks had no manufacturer's recommended method to field-verify their accuracy and no way to digitally record or transmit the torque applied to one or more connections. This has undoubtedly resulted in unnecessary expense from lost and damage drillpipe and other downhole tools. The economic impact of the problem is significant and warrants structured, collaborative approach for a solution.
In mid-2014, a collaborative group, including an operator, a drilling contractor and multiple vendors and original equipment manufacturers (OEMs), began the first parts of a six-sigma DMAIC (Define-Measure-Analyze-Improve-Control) cycle to improve make up torque process capability. The effort involved the manufacture of a fit-for purpose tool to measure applied torque and an exhaustive study of multiple makes, models, contractors, operators and operating conditions. The results of the study demonstrate that the process of making up drillpipe with iron roughnecks is uncontrolled (from a statistical perspective). It is also shown that the tools, as they currently exist, deviate significantly from customer defined process capability.
Further study is required to address all the common and special cause variations in the process. Moreover, OEMs, contractors and vendors must work together to implement process controls.
Solid Expandable Solution to Qualify Existing Non-Sour Service Production Casing
Authors: Contreras Jesus D. , Gamarra Francisco , Becnel Joe L. , Phillips Conoco , Galloway Greg 
Published: January 2016

Abstract
In the early development of the Eagle Ford Field in South Texas, the initial well design equipped wells with non-sour service P-110 production strings. After the early stages of production, some of these early wells were found to produce increasing levels of H2S, which posed the problem of potential sulfide stress cracking at shallow wellbore depths because of relatively high H2S partial pressures and associated low formation temperatures (&lt;145°F). To mitigate this risk, production packers were run to protect the production casing in flowing wells with H2S partial pressures of more than 0.05 psi. As these wells were depleted to lower flowing pressures, production was maintained by intermittently producing. This method was used because of limited or no artificial lift options for wells with non-sour-service production casing. A solution allowing artificial lift was needed to better maintain and sustain production, to extend the utility of these wells, and to allow future recovery of the potential reserves.
Expandable casing technology was ultimately chosen as a solution to maintain well integrity and enable implementation of artificial lift (gas lift). This operation involved the running of an expandable liner to cover and protect the section of the casing susceptible to sulfide stress cracking. A solid expandable tubular designed to support the corrosive environment was successfully tested and qualified for sour service in extreme corrosive conditions by the operator metallurgists, adhering to sour service qualification according to paragraph A.2.1.6 and Annex B of NACE MR0175/ISO 15156 standards.
Additional testing was performed to ensure that the required length of the chosen liner could be run while being held at surface. Normally, these liners are left free at the top which allows slight shrinkage in length to avoid high tensile forces as the liner is expanded outward. The liner system passed all tests performed independently by the service company. The team proceeded to install the solid expandable liner, from 7,047 ft. (where the temperature was above the threshold of H2S embrittlement) to surface to protect the existing 5 1/2-in. 20 ppf P-110 casing. The internal D-diameter (ID) of the completion changed from 4.778 in. (original production casing size) to 4.140 in. (once the pipe was expanded). The well was then completed with 2 3/8-in. tubing, a production packer, and traditional side-pocket-mandrel gas lift. Currently, the well is producing on continuous gas lift with the casing protected by the expandable liner. The expandable liner provided an enabling solution that allowed implementation of the optimal artificial-lift method to recover additional resources within the drainage area.
First Successful Implementation of an Advanced Fibrous Organic Based LCM and Optimized Casing Design in Europe: A Case History From Drilling a 6022 m HPHT Exploration Well in Vienna Basin, Austria
Authors: Abdelaal Khaled , Ovrevik Kjell , Knezevic Rudolf-Nikolaus , Husodo Ryanto 
Published: January 2016

Abstract
The paper presents findings of a case history based on the first application of specialized organic fibre lost circulation materials (LCM) in Europe. It lists technical challenges encountered during the recent drilling of HPHT exploration well Stripfing T1 to 6022 mMD and describes how new fibrous organic LCM have proven their value in a range of lost-circulation applications in the Vienna basin. The paper will also elaborate on the narrow mud window available and the main drivers for well design along with contingency concepts.
The operator identified an innovative LCM which had the characteristics that it is plastic, deformable and can be squeezed into a loss zone resulting in an effective seal being formed across the loss zone with an internal filtercake rather than a high loss filtercake forming on the exterior of the wellbore. Several pills containing this product were used achieving excellent results when applied according to a specific procedure. The paper will look in detail at this procedure and highlight the input from detailed decision-tree charts, and the characteristics and wettability of fibres.
The Vienna Basin has a history of mud losses ranging from continuous seepage to severe losses. The main concerns while planning the Stripfing T1 well were the magnitude of overpressure in combination with the expected losses. The above had been the root cause of previous failures.
Several attempts to cure the losses with standard LCM had proven unsuccessful, as a consequence the operator decided to adopt a new approach using a specialized LCM product in order to avoid running casing earlier. Successful implementation of this advanced technique allowed the operator to drill the well using only 3 casing strings and a final hole size of 8 ½ in. without reducing the mud weight.
The level of success achieved by using these materials suggests it should be considered as the preferred standard practice for curing any type and volume of losses.
Data Ownership for Drilling Automation – Managing the Impact
Authors: Macpherson John , Wardt John de , Laing Moray , Zenero Nathan 
Published: January 2016

Abstract
Drilling systems automation depends on timely flow of accurate and relevant data from multiple sources to control equipment, machines and processes. The fragmented nature of the drilling operations business means that data must usually be shared among companies contracted to perform services, and the operator, and all companies must trust that data. This paper describes the issue of data ownership in terms of the application of drilling systems automation, and proposes solutions.
Various parties in a drilling operation measure, collect, analyze and report data gathered during the drilling operation. They take actions to control the drilling process, avoid problems and improve performance, using information derived from the data. Data is used in pre-job planning, in real-time by those operating the drilling rig and various drilling tools, as well as periodically to advise the onsite drilling team. Data flow ranges from high-frequency, low-latency response loops at the wellsite to low-frequency, high-latency response loops in remote centers.
The SPE Drilling Systems Automation Technical Section (DSATS) has identified OPC UA as the most suited communications protocol for multidirectional fast-loop control systems. In these environments, there is high likelihood that a controller from one supplier will access and use data created by another supplier.
Drilling systems automation requires structured and organized data sharing between parties. This data sharing adds value to the drilling process. A conceptual data model describes at least three classes of data generated while drilling, and all lie within the confidentiality envelope of the operator or government agency. There is data that is the property of the data generator (such as equipment condition monitoring data), data that is restricted (such as formation evaluation data), and data that is shared in an "open data pool" for the purposes of drilling systems automation. Because ownership or control means responsibility for data quality, it is important that each data generator own its contribution to the shared data pool. The data aggregator – the party managing the shared data pool – is therefore not necessarily the owner of all data in the pool, but a caretaker of that data.
This paper describes the history of data measurement, data flow and data ownership in the drilling industry. It will address data ownership issues pertaining to drilling systems automation and drilling performance improvement. A brief review of examples of data from academia and from within our own industry will assist in understanding the relationship between data ownership and intellectual property. The paper presents a data ownership and data sharing solution that provides an environment for drilling systems automation.
Casing Integrity: Modeling Strength Degradation
Authors: Li Changning , Samuel Robello 
Published: January 2016

Abstract
Casing integrity management is crucial, especially in wells experiencing severe casing wall degradation. It is highly desirable to predict the threshold pressure for degraded casing burst and collapse strength and to design the casing strings considering these wear effects. Knowledge of stress distribution in worn casing helps predict where casing failure occurs first. This study focuses on building a model for stress distribution along the casing circumference based on "crescent-shape" casing wear. A common method is to estimate the reduction of the casing burst strength in worn casing using the API burst strength equation with a linear reduction by the remaining wall thickness or wear percentage equivalent to a "uniformly-worn" casing model. This paper presents a rigorous engineering method to calculate the hoop strength directly, including the local bending in the thinner portion of the "crescent-worn" casing.
A model and correlation to calculate varying hoop strength in the crescent-worn shape and non-worn casing have been developed with force and moment balance equations. The stress predicted in this paper is similar to the results obtained from the finite element method (FEM), which validates equations and results obtained from this paper. The developed model is generic and can be used for casings, risers, and tubings.
Lost Circulation Management in Naturally Fractured Formations: Efficient Operational Strategies and Novel Solutions
Authors: Savari Sharath , Whitfill Donald L. 
Published: January 2016

Abstract
Managing severe to total lost circulation can be very challenging in naturally fractured formations. Particulate lost circulation materials (LCMs) have been used to manage lost circulation for many years; however, current LCMs are not efficient in terms of their size and application methods when it comes to curing severe to total losses, such as highly fractured formations.
In the present paper, preventive (proactive) and remedial (reactive) operational strategies will be discussed. In addition to the operational strategy, this paper will also present novel additives in the form of engineered composite LCM solutions (ECS) with multi-modal particle-size distribution (PSD), which were successfully used to manage severe-to-total-loss situations in naturally fractured carbonate formations. The multi-modal PSD will help manage any uncertainties in fracture sizes, and the presence of larger particles will also aid in plugging large fractures. Case studies will be presented for applications in the mid-continental USA, Middle East, and offshore East Africa.
Preventive strategies are recommended to reduce the potential for lost circulation (LC). It is recommended that LC management be considered in the wellbore planning/design phase and that all engineering analyses be performed prior to the start of drilling the well. It is very important to have remedial strategies in place if the preventive plan does not work. This includes putting loss contingency plans in place should unexpected loss events occur. Examples will be discussed as to how previous knowledge and lessons learned can play a critical role in developing contingency engineered solutions to effectively cure losses.
When managing severe-to-total losses in highly fractured formations, particulates alone may not be effective. The combination of a large multi-modal PSD LCM, a swellable component, and chopped synthetic fibers were proposed as a solution for dealing with such extreme losses. While drilling highly fractured formations, this combination was applied after all conventional LCM applications failed. In most cases, the combination was pumped open-ended, and losses were totally cured so that circulation could be re-established. To conserve rig time, the use of a treating sub is recommended as part of the BHA for handling high concentrations of large PSD LCMs for curing severe losses.
The combination of operational strategies (LCM applications) and novel LCM solutions for curing severe-to-total losses in naturally fractured formations are the technology improvements presented in this paper.