bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digital Rock Technology for Quantitative Prediction of Acid Stimulation Efficiency in Carbonates
Authors: Klemin Denis , Nadeev Alexander , Ziauddin Murtaza 
Published: September 2015

Abstract
The complex pore structure and porosity in carbonate rocks have a strong influence on the stimulation efficiency of the acid. Recently, it was shown that nondestructive tracers can be used to predict pore volume of acid to breakthrough (PVBT) for both plain and emulsified acids [1, 2]. The present study explores the use of digital rock technology to simulate tracer injection in carbonate rocks. The accuracy of the digital rock method is compared to the laboratory measured values for five carbonate rocks of different porosity types and heterogeneity scales. The digital rock simulations are performed by an industry-unique direct hydrodynamic pore flow simulator that operates on pore geometries from digital rock models obtained from 3D scanning electron microscope images. The pressure-volume-temperature and rheological models used in the simulator represent real treatment and reservoir fluids. Fluid-solid interactions are introduced using distributed microscale wetting properties. The simulator uses the density functional approach applied to the hydrodynamics of complex systems. The simulations are used to calculate a measure of the accessible rock volume which is then used to predict the acid response.
Conventional laboratory testing methods require large volumes of formation rocks for optimization of acid type and volume and it often prohibitively expensive. The digital rock methodology has the potential of significantly reducing the required volume of formation cores, which could be an enabler for more frequent carbonate porosity specific stimulation optimization. The present study explores the limits of its applicability.
Flow-loop Testing of Subsea Produced Water Quality Monitoring Sensor Prototypes
Authors: Yin Xiaolei , Moore Patrick , Gul Kamran , Lachance Jason 
Published: September 2015

Abstract
Re-injection of produced water can be a cost-effective way of disposing produced water and improving hydrocarbon recovery for subsea production and processing systems in deeper water or with long tieback distances. Injecting produced water with high oil-in-water content and suspended solids into a well can be detrimental to relative permeability in the formation near the wellbore region causing loss of well injectivity over time. Monitoring re-injection water quality trends can provide an early indication of injectivity decline and potentially avoid loss of an injection well.
As the industry moves closer to having a fully-functioning subsea production and processing system, there has been an increased effort in developing reliable in-line subsea Produced Water Quality Monitoring (PWQM) technologies. Such monitoring sensors can measure the quality of re-injection water in terms of oil and solids content (size and concentration) thereby facilitating performance monitoring of subsea separation and produced water treating systems by identifying upset conditions.
Development efforts to meet subsea PWQM requirements for produced water re-injection application included: (1) development of subsea sensor concepts with active cleaning systems to enable long term operation without compromising performance, and (2) extension of the Oil-in-Water (OIW) measurement range significantly to support subsea production/processing and produced water reinjection applications. The new sensor designs that were developed primarily for subsea application for improved measurement performance and with self-cleaning functionality can also be used topsides.
Two different PWQM sensor prototypes were developed to meet the subsea PWQM requirements. The measurement performance of both prototypes was verified in a flow-loop by comparing the measurement readings with known reference. The impact of variations introduced in test conditions such as changes in pressure, temperature, salinity, and flow velocity on the performance of the prototypes was also investigated. The active cleaning systems were also tested to examine their effectiveness under normal and simulated fouling conditions.
The paper discusses the technical gaps in subsea PWQM technologies, flow-loop testing of the PWQM sensors prototypes and the key test results.
Identifying Leading Indicators to Address the Risk of Drilling and Completions for Shale Gas
Authors: Tamilselvan Prasanna , Das Bibek 
Published: September 2015

Abstract
A successful drilling and completions operation for Shale Gas is the key to ensure wellbore integrity throughout the life of the well. Drilling for shale gas involves a lot of uncertainty regarding the geology, geography and well geometry (3G's). It is thus imperative to identify the leading indicators for failures to avoid the costly measures later required to solve operational problems and reduce non-productive time. However, the uncertainty factors (3G's) vary for different regions like Marcellus and Barnett shale; as well as for different wells in the same region as seen in the Eagle Ford shale play. Hence it becomes difficult to implement the know-how of one region to another region.
This paper proposes a novel framework to identify leading indicators to address the risk in shale gas drilling and completions. The proposed framework is divided into three main parts: (i) collection of past failure data, 3G parameters and real-time monitoring data; (ii) estimation of real-time damage growth using the proposed model that combines physics based failure model and data collected from previous stage; (iii) identification of leading indicators and estimation of reliability parameters and updating those to the “live” databases. The paper includes a case study on casing failures related to shale gas operations.
The specific failure mechanism that is often seen in shale operations is brittle longitudinal splits of couplings. This paper discusses the failure analysis of longitudinal splits of P-110 casing. The study then identified the leading indicators based on the failure analysis. The sensitivity studies on variability of initial damage level and loading on the stochastic damage propagation model are also conducted.
The sensitivity study results show that the damage propagation is largely influenced by the variability of initial damage level and loading process. This paper also suggests leading indicator mapping process. This includes maintaining a database on mapping of generic failures and their corresponding leading indicators. This enables the analyst to use the data from different regions interchangeably by extending the boundaries of failure analysis.
Long Range Electromagnetic Telemetry Using An Innovative Casing Antenna System
Authors: Chen Jiefu , Li Shanjun , MacMillan Clayton , Cortes German , Wood Drew 
Published: September 2015

Abstract
Wireless data transmission is an essential part of measurement-while-drilling (MWD) or logging-while- drilling (LWD). It can be achieved by several different technologies, such as mud pulse telemetry or electromagnetic (EM) telemetry. Compared with mud pulse telemetry, EM telemetry has been proven to have better reliability and relatively faster rates of data transmission. However, EM telemetry may suffer severe signal attenuation when conductive formation layers exist between bottom hole assembly (BHA) and the surface.
An innovative casing antenna system has been developed to alleviate the signal attenuation issue of EM telemetry. A transceiver is set on the surface connected with two coaxial cables. One cable is externally attached to a casing string and connected to the bottom of the casing; the other cable is placed at surface connected to either the blowout preventer (BOP) or a metal stake driven into the ground with a certain distance away from the rig. Telemetry signals are propagating between the surface transceiver and the borehole transceiver via underground formation.
The new system essentially measures the potential differences between the bottom of the casing string and one point near surface. On the contrary, conventional EM telemetry measures the potential differences between two locations on the surface. The innovative deployment of this casing antenna makes the new telemetry system be able to avoid heavy signal attenuation caused by any low resistivity layers above the bottom of casing, and consequently it has much larger operation depth than conventional EM telemetry. Numerical studies also show that this new telemetry technology has less signal drop as the working frequency increases; in other words, it can provide higher rates of data transmission.
In this paper we will describe the setup of the casing antenna system, explain the working principle of this innovative method, and compare the new system with traditional EM telemetry system. Numerical simulations as well as filed data will be given and discussed to demonstrate the advantages of this new technology over conventional EM telemetry.
Revealing the Benefits of the Intelligent Well Pad Program for Onshore Shale Assets
Authors: Krome J. D. , Bloom M. H. , Swanson A. B. , Anthony D. , Derise S. , Rightmire L. 
Published: September 2015

Abstract
Though many of the US shale plays have been developed in just the last few years, there remain new producing assets that lack the latest technologies and best-in-class working practices. Retrofitting these assets with now-commonplace digital oilfield-type automation, information technology (IT), and work practices have revealed significant benefits to BHP Billiton (BHPB) in the Eagle Ford shale. This paper will describe how BHPB, after purchasing the Petrohawk Eagle Ford shale assets, recognized the potential for improvements, and used Karnes County wells as a demonstration area for its Intelligent Well Pad Program (IWPP).
A multi-disciplined team evaluated the opportunities and implemented a comprehensive program of facility redesign, wellsite automation, IT & Telecommunications, and a 24/7 surveillance center. A detailed assessment, with all key stakeholders, yielded a fit-for-purpose program, detailed and tailored for this specific application.
The IWPP, deployed over a 12-month period, is showing improved results in HSE (via reduced personnel exposure to driving on dangerous rural roads and well pad hazards), Production (via reduced downtime), and Cost (via increased well count / operator). Based on these early positive results, BHPB are now developing and tailoring its IWPP solutions and working practices across all of its shale assets, as a key aspect of greenfield well pads.
Making the Impossible Possible with MPD Application on 0.4 ppg Mud Weight Window – A Case History Successful Automated Managed Pressure Drilling, Managed Pressure Run 11 ¾” Liner & 9 5/8”Liner (Tieback Liner), and Managed Pressure Cementing in a Semisubmersible Offshore Sarawak Malaysia
Authors: Tang Jose , Prasetia Andi Eka , Gallo Fernando , Rojas Freddy , Rubianto Irwan 
Published: September 2015

Abstract
The JST-1 well is an offshore High Pressure and High Temperature (high pressure by gradient which was more than 0.1 psi/ft) exploratory well, located in the block SK 301A.
The primary objective was to evaluate the hydrocarbon potential in Cycle VII and Cycle VI, at the depth of 2374 and 2794 mTVDDF respectively with anticipated reservoir pressure of 5476 and 6898 psi with temperatures from 226 to 264 °F at well TD 3477mMDDF/TVDDF the pressure and temperature was predicted to be 9276 psi and 302 °F.
The well was initially planned to be drilled to 2979 mTVDDF in 12 ¼” hole section and 8 ½” hole section until 3477 mTVDDF. The degree of uncertainty in JST-1 pore pressure and fracture gradient estimates are highly uncertain. This was due to the reason that the offset wells, S-1 and L-1 are very far away from JST-1, approximately 33 km away to the North West and 35 km to the North East respectively. In addition, none of the offset wells have been drilled deeper than 2879 mMDDF. Therefore, high case pore pressure and fracture gradient estimates were used for the well design and planning.
Based on cementing simulation for the 11 ¾” liner, 9 ⅝” casing cementing jobs, the resultant cement slurry Equivalent Circulating Density (ECD) will fracture the formation while the cement is pumped into the open hole. Hence, the Managed Pressure Drilling (MPD) method was used to drill hole sections lower than 13 ⅜” casing as well during the cementing job and running in hole with 9 ⅝” casing.
This paper aims to describe the application of Automated MPD on this specific well from conceptual to planning to finally execution. Moreover, with the intention to share the challenges observed during execution as well as the decisions taken to overcome these challenges and finally the 5 steps strategy to ensure the well was stable.
Maximizing Well Deliverability in the Eagle Ford Shale Through Flowback Operations
Authors: Deen Toby , Daal Johan , Tucker James 
Published: September 2015

Abstract
Flowback procedures for wells producing from sub-normally or normally pressured reservoirs are usually straightforward and non-technical due to the short flowing periods that are inherent with low pressure wells. Over-pressured formations can naturally flow for several months and even years. However, uncontrolled procedures can potentially affect the well productivity and its profitability. Flowback techniques for wells flowing from over-pressured reservoirs can vary widely and have a significant impact on short and long term economic performance.
This paper focuses on the evolution of flowback operating procedures for wells in the Eagle Ford shale play and highlights how these procedures can impact short and long term well performance. The workflow demonstrates how choke management, or drawdown strategies, can influence potential damage mechanisms in the reservoir, completion and wellbore. Techniques are then presented for using rate transient analysis (RTA) that allows for a robust understanding of early time well performance while also monitoring for damage downhole. The data shows that using RTA with high frequency data to help drive operational decisions during the flowback period can deliver optimal drawdown procedures and maximize well deliverability. This in turn maximizes time sensitive economic metrics by taking full advantage of variables like the well's completion efficiency and stimulated volume.
The drawdown management workflow outlined in this paper has proved to significantly outperform predetermined choke procedures that have historically been common practice in industry. Results also show how practical field applications of technical interpretations can be used on a daily basis to significantly increase value and drive operational efficiencies in the field while minimizing the potential risk of damaging the completion.
Liquid Loading of Highly Deviated Gas Wells from 60° to 88°
Authors: Alsaadi Y. , Pereyra E. , Torres C. , Sarica C. 
Published: September 2015

Abstract
Liquid loading, a common problem in matured gas fields, is investigated experimentally in highly deviated gas wells. The experiments were carried out using air and water in a 3-in ID pipe at well deviation from 60° to 88° from vertical. Pressure gradient and liquid holdup were measured, and flow pattern characteristics as well as onset of liquid loading were observed using video recordings. The results shown a significant effect of the deviation angle on the onset of liquid loading. Benchmark of the results with several two-phase mechanistic models show poor predictions for the pressure gradient but good agreement for liquid holdup.
How Far Can We Push the Boundary of Horizontal Drilling? A Rivalry Between Wellbore Friction and Drillpipe Buoyant Weight and Stiffness
Authors: Mehrabi Mehran , Miska Stefan 
Published: September 2015

Abstract
To estimate the maximum attainable reach for a horizontal wellbore one needs to investigate the rivalry between the amount of available driving force and the opposing frictional forces. As we provide more driving force through further slack-off, we are more likely to buckle the string and create large normal contact forces, which result in additional tangential frictional forces opposing the forward motion of the BHA. In other words, all the provided driving force will not be transmitted to the desired point (i.e. drillbit) along the string. The greater the stiffness of the drillpipe, the later it buckles and comes into contact with the wellbore wall to create additional normal forces. However, greater stiffness might come with greater weight, as is the case for Steel Drillpipe (SDP) compared to Titanium Drillpipe (TDP), Aluminum Drillpipe (ADP) and Composite Drillpipe (CDP).
In this study a new approach for modeling the coupling between tangential frictional force and normal contact force between wellbore and helically-buckled drillstring is developed. The validity of the model is confirmed with experimental data available in the literature. The axial force transfer capability of drillstrings made of SDP, TDP, ADP and CDP are compared. For a limited amount of compressive force provided at the beginning of the horizontal section, different categories of pipes (in the horizontal section of the well) take on different configurations. In addition, along a drillstring some parts remain straight, while some parts buckle helically or sinusoidally. This makes different drillstrings transfer the same amount of provided load differently. In practice, we are able to supply a limited amount of compressive load close to the critical lock-up load in the vertical/slant section of the wellbore. Moreover, below a minimum weight on bit (WOB) drilling becomes impractical. After simultaneous consideration of different buckling modes along the entire drillstring, it is quantitatively shown under what condition ADP can be considered as a superior option over CDP to be used in the horizontal section; and why ADP and CDP have shown a remarkable increase (almost two to three times larger) in the attainable horizontal reach compared to TDP and SDP. This article helps drilling engineers to design an optimum hybrid drillstring for ultra-extended-reach-wells.
Case Studies Validate the Effectiveness of Aluminum-based HPWBM in Stabilizing Micro-Fractured Shale Formations: Field Experience in the Peruvian Amazon
Authors: Arambulo V. H. , Colque J. N. , Alban E. D. , Ahmed R. M. 
Published: September 2015

Abstract
One of the most important functions of drilling fluids is to maintain adequate wellbore stability until casing is run and cemented properly. Lack of wellbore stability generates an enlarged non-homogeneous elliptical weaker borehole. This non-cylindrical shape of the wellbore leads to complex drilling problems such as poor hole cleaning, high solids production, stuck pipe, unsuccessful wireline runs, poor cement bond representing large cost to operators.
Micro-fractured shale formation represents a challenge due to its natural lack of stability when exposed to conventional water-based mud (WBM). As a solution, oil-based mud (OBM) becomes a technical option to overcome the issues observed with conventional WBM. It tremendously reduces the chemical interaction with micro-fractured shales. However, environmental constraints of the OBM makes this option non-applicable for environmentally sensitive areas. According to recent publications, with similar complicated environments, Aluminum-Based High-Performance Water-Based mud (HPWBM) has shown good performance with features closely comparable to that of OBM.
The Peruvian Amazon has the largest Peruvian oil and gas reserves. However, it is located in an environmentally sensitive area marked by a large biodiversity and native communities. Environmental concerns related to drilling activity are very restrictive. Furthermore, most operations are performed as “offshore on land” (i.e., helicopter-transportable operation) where drilling fluid management cost strongly affects the final Well’s Authorization for Expenditure (AFE). Aluminum-based HPWBM has been successfully introduced recently in the Peruvian Amazon for drilling vertical and deviated wells resulting in considerable improvement in drilling performance and goal achievements. Issues related to shale instability were previously reported and financial losses forced operators to use Aluminum-Based HPWBM to reduce non-productive time and associated costs.
Two groups of case studies from four wells drilled in Blocks 8, 56 and 88 blocks of the Peruvian jungle are presented in this paper. A Wellbore Quality Index (WQI) tool and Key Performance Indicators (KPI) are introduced to make comparison between aluminum-based HPWBM and previously used (i.e. conventional) fluid systems and to validate the effectiveness of the aluminum-based HPWBM system in stabilizing micro-fractured shale formations. A proper fluid design was selected during the planning phase of each project and fluid properties were monitored at the rig site to evaluate performance. In addition, wireline logging, casing runs, trips, wellbore quality and drilling performance were closely monitored to examine the impact of using aluminum-based HPWBM. Results show tremendous performance improvement introducing a new benchmark in drilling operation in the Peruvian Amazon.
A Case Study of Using Expandable Liner Hangers and Advanced Cementation Techniques for ERD Wells in India
Authors: Lobo Monali , Singhal Ashish , Lang Clifford , Kolay Jayabrata , Sinha Pankaj , Kant Ravi , Varghese Roy , Doodraj Sunil , Li Jason , Kumar Animesh , Kestwal Ashish , Vaibhav Ankit 
Published: September 2015

Abstract
This paper explains the successful execution of Expandable Liner Hanger and primary cementing job for ERD wells in Rajasthan block of North-West India. One of these wells has the longest horizontal 6in. hole section in the Indian Subcontinent. Zonal isolation is especially critical, as these wells are all candidates for multistage fracturing operations in the completion phase.
The successful liner job in these wells face several challenges: placement of 4½ inch liner in 6 inch hole, hole conditioning, cement placement and ECD challenges due to low fracture gradient limit.
An integrated Basis of Design was developed to mitigate the challenges. This includes The placement of liners with computer aided torque & drag analysis,Rotation of liner during hole conditioning & cementing at highest possible rpm within acceptable torque limits,Fine tune fluid properties with computer aided simulator to achieve sufficient cement coverage around the liner (displacement efficiency).
The liner hanger system in this case study has an advanced running tool to facilitate the required rotating capability. The liner hanger also incorporates a contingency tertiary setting mechanism for liner expansion due to the challenging down hole condition. The expandable liner hanger is an integrated hanger packer system. Elastomeric elements are bonded on to the hanger body itself. As the hanger body is expanded, the elastomeric elements are compressed in the annular space, which provides primary annular isolation at liner top.
This case study also examined the impact of liner rotation on displacement efficiency of the cement slurry with computer aided Finite Element Analysis. The results give engineers a better understanding of the relationship between rpm and displacement efficiency of the cement slurry.
The technology and the practices established from this case study have become the standard operating procedures for liner cementing jobs in subsequent ERD wells.