bluuebunny/crossref_metadata_2025_split huggingface dataset:
Focus on Reducing Cost of Ownership Drives the Development of the 4th Generation Drill Pipe Connection Design
Authors: Plessis Guillaume , Muradov Andrei , Morgan Dan , Brock Jim , Primeaux Alan 
Published: October 2018

Abstract
The past three decades saw the introduction of several generations of double-shouldered drill pipe connections with performance as a primary development focus. The record extended-reach drilling (ERD) wells could not have been drilled and completed without these technological advancements, which brought more torque, enhanced hydraulics, and greater reliability to satisfy drillers’ needs. The improved performances of these technologies were so enabling that the associated repair costs were deemed acceptable.
When these same connections started to be used on land rigs to deliver wells in a factory drilling fashion, where cost control is of higher importance, the cost of maintaining these premium connections started to become more of an issue. Therefore, it became obvious that a different approach was required to meet the combined need for both performance, as well as a lower total cost of ownership post-acquisition.
A comprehensive two-year research and development (R&D) program was carried out to evaluate various design options. After a three-month field trial, the connection was released and has been used in the field since the second quarter of 2017.
The 4th generation double rotary-shouldered connection design provides benefits in addition to the previously seen improvements in torque, hydraulics, and streamlined profile. Specifically, the design optimizes the connection stresses, has broader tolerances for field damage, reduces the material loss on repairs, and provides greater connection ruggedness, all increasing field life and reducing operating cost.
The 4th generation double-shouldered connection was used in various onshore and offshore fields, accumulated a high number of drilling hours and has been inspected multiple times.
This paper demonstrates the performances of this new rotary-shouldered connection, its ruggedness and suitability for use on various kinds of rigs, and confirms the lower repair rates and reduced operational cost of ownership. As rental strings are rotated from rig to rig, they are prime candidates for evaluating these factors. Data compares the field damage and repair frequency of this new connection with earlier generation connection designs.
Zonal Isolation in Horizontal Configurations: Dynamic Cement Placement Approach Applied in Argentina, a Case Study
Authors: Ficetti S. , Silva P. , Revilla R. , Torgau N. , Carestia N. 
Published: October 2018

Abstract
The increasing energy demand has led shale unconventional reservoirs to become a focal point for operators worldwide. Over the past decades, several technological advances were conveyed to drilling and completing horizontal geometry wells in which massive hydraulic fracture treatments are deployed to improve production of these reservoirs.
Argentina has one of the largest shale-stored hydrocarbon reserves in the world and has become one of the leading countries in the exploration, appraisal, and development of unconventional reservoirs. The number of horizontal shale wells drilled in the country increased over the past decade, generating the need to find solutions to cement horizontal laterals and achieve the required zonal isolation for the normal completion and production of these wells, preserving well integrity.
Based on the difficulties encountered to cement these horizontal wells, such as channeling and differential fluid velocities, among others, the need to implement casing rotation while cementing was considered. This mechanical method has remained locally as one of the least accepted solutions because of the fear that the high torques during the operations would cause casing failures.
In a recent unconventional campaign, casing rotation was applied during well conditioning and along the cementing operation. A sensitivity study to rotational speed was performed, and the cementing design was optimized with a new 3D annular displacement simulator (3D-ADS) that predicts annular flow in complex geometries, accounting for pipe movement. The well was cemented successfully, obtaining congruent results from comparing bond logs and fluid placement simulations.
This study defines some of the factors contributing to a successful cementing job in a horizontal geometry, the aspects to be analyzed from the cementing perspective when rotating casing to aid in mud displacement, and the evaluation of the wells cemented under these circumstances compared to the simulated results predicted during the design phase of the well.
Interpretation of Nuclear-Magnetic-Resonance Response to Hydrocarbons: Application to Miscible Enhanced-Oil-Recovery Experiments in Shales
Authors: Dang Son T. , Sondergeld C. H. , Rai C. S. 
Published: October 2018

Summary
Estimation of total reserves in shale/gas and shale/oil reservoirs is challenging but critical. Different logging tools and core-evaluation procedures are used to address this challenge. Nuclear magnetic resonance (NMR) plays a vital role in understanding fluid content, rock/fluid interaction, and determination of pore-body-size distributions. Hydrocarbon (HC)-hosting pore systems in shale includes both organic and inorganic pores. Recoverable HCs include bitumen and light HCs. Their relative fractions are strongly dependent on thermal maturity. Regardless of detailed chemical characterization, “bitumen” is simply defined on the basis of mobility in this study. The apparent mobility of HCs depends on fluid composition, solubility, and reservoir temperature. Historically, NMR laboratory-calibration measurements (nominally, 2-MHz) on core are conducted at room temperature (25–35°C). This study highlights the importance of running NMR tests at reservoir temperature. Experiments were performed for both bulk fluids and fluid-saturated rock samples.
The results show that, at a specific temperature, NMR responds only to the fraction of HCs present in the liquid phase. For routine NMR measurement, at 31°C, only the relaxation signals of compounds more volatile than C17 are acquired. Thus, the C17+ fraction would be invisible to NMR at room temperature, but perhaps not at reservoir temperature. This is critical to the interpretation of NMR log response within the early oil and condensate windows, in which C17+ can be a major fraction. Thus, engineers can underestimate movable HCs by using routine core data as a basis for interpretation.
On the basis of NMR experiments for several oil samples, we observed that the T1–T2 distributions depend on the overall composition of total HCs and effective mobilities. The results also show that, in the case when both light and heavy HC fractions coexist in a single phase, they do not appear as different clusters in a T1–T2 distribution map. NMR parameters were used to monitor the amount, composition, and effective mobility of remaining HCs after each injection and discharging cycle, during miscible enhanced-oil-recovery (EOR) huff ’n’ puff experiments on Eagle Ford samples.
Rapid Evaluation of the Permeability of Organic-Rich Shale Using the 3D Intermingled-Fractal Model
Authors: Li Caoxiong , Lin Mian , Ji Lili , Jiang Wenbin , Cao Gaohui 
Published: October 2018

Summary
Shale possesses abundant micro/nanopores. Most micro/nanopores that exist in organic-rich shale are organic pores and mainly developed in organic matter. The pore distribution in matrix space significantly affects gas percolation and diffusion. Pore-size distribution possesses a self-similar, or fractal, property. The pore space and gas permeability of shale can be easily rebuilt and evaluated, respectively, using fractal theory. In this work, a 3D intermingled-fractal model (3D-IFM) is successfully built using scalable scanning-electron-microscopy (SEM) images of shale samples. 3D-IFM is made up of several components, including organic pores in organic matter and in pyrites, inorganic pores, slits, and matrix. An improved pore-connective-calculation method is also introduced to evaluate the apparent gas permeability of the shale model. The proposed 3D-IFM rapid-permeability-evaluation method for organic-rich shale is valid and useful and considers the main components of shale. This method can rapidly evaluate apparent gas permeability and simplify the apparent-gas-permeability-calculation process. Thus, the method provides a promising means of rapidly evaluating apparent gas permeability.
Integration of 4D Seismic in Steam-Assisted-Gravity-Drainage Reservoir Characterization
Authors: Hadavand Mostafa , Carmichael Paul , Dalir Ali , Rodriguez Maximo , Silva Diogo F. , Deutsch Clayton V. 
Published: October 2018

Summary
4D seismic is one of the main sources of dynamic data for heavy-oil-reservoir monitoring and management. 4D seismic is significant because seismic attributes such as velocity and impedance depend on variations in reservoir-fluid content, temperature, and pressure distribution as a result of hydrocarbon production. Thus, the large-scale nature of fluid flow within the reservoir can be evaluated through information provided by 4D-seismic data. Such information may be described as anomalies in fluid flow that can be inferred from the unusual patterns in variations of a seismic attribute. During steam-assisted gravity drainage (SAGD), the steam-chamber propagation is fairly clear from 4D-seismic data mainly because of changes in reservoir conditions caused by steam injection and bitumen production. Anomalies in the propagation of the steam chamber reflect the quality of fluid flow within the reservoir. A practical methodology is implemented for integration of 4D seismic into SAGD reservoir characterization for the Surmont project.
A New Analytical Solution of the Triple-Porosity Model for History Matching and Performance Forecasting in Unconventional Oil Reservoirs
Authors: Qiu Kaixuan , Li Heng 
Published: October 2018

Summary
Production data from hydraulically fractured horizontal wells in ultralow-permeability reservoirs have been observed to exhibit a half-slope straight line on a log-log plot of rate vs. time. Using these observations, many analytical models of linear flow have been developed to analyze the well performance in these reservoirs. However, it is relatively complicated to solve these models with the Laplace transform and numerical inversion. In this paper, a new analytical solution of a triple-porosity model is derived for unconventional oil reservoirs. The partial-differential equations (PDEs) are transformed into ordinary-differential equations (ODEs) by integration, instead of the Laplace transform. A rate-vs.-time solution in real-time space can be obtained, bypassing the numerical inversion for the Laplace transform. Our model is validated by comparison with both the numerical-model and Laplace-transform solutions. The physical meanings of the model parameters are analyzed through sensitivity analysis. The new model is then applied to field-production data for history matching and forecasting. Besides matching the production data, the pore volume (PV) of the matrix and fracture media can be estimated, which helps quantitative analysis of unconventional reservoirs.
A Comprehensive Work Flow To Characterize Waterflood-Induced Fractures by Integrating Real-Time Monitoring, Formation Test, and Dynamic Production Analysis Applied to Changqing Oil Field, China
Authors: Wang Yang , Cheng Shiqing , Zhang Kaidi , He Youwei , Feng Naichao , Qin Jiazheng , Luo Le , Yu Haiyang 
Published: October 2018

Summary
It is well-known that water injection may induce formation fracturing in tight reservoirs. Especially when the field-geology condition is complex and the waterflood-induced fractures (WIFs) are not well-identified in time, the induced fractures can be of the same order as the well spacing, which has a significant, and generally undesired, impact on both areal sweep and vertical conformance. Therefore, the onset of WIFs must be identified in a timely manner, and the waterflooding performance must be evaluated comprehensively to formulate an appropriate strategy over time.
A new work flow, containing analytical/semianalytical, statistical, and numerical techniques that are based on flow-rate/BHP and formation-testing data, is applied to identify the WIFs, diagnose waterflooding direction and front distribution, analyze interwell connectivity, and interpret abnormal bottomhole-pressure (BHP) behaviors in the Changqing Oil field. The work flow includes three modules: First, real-time monitoring and analysis, including modified Hall plot, evolving skin analysis, and injection/fracturing index methods, are used to identify the start of WIFs. Then, the formation-testing module, consisting of step-rate test (SRT), radioactive-tracer logging, and passive seismic method, is applied to investigate the formation-fracturing pressure, and uneven waterflooding performance in the areal and vertical directions. On the basis of the two former modules, we adapt the third module, which includes injector/producer relationships (IPRs) and the constrained multiple-linear-regression (MLR) method, to quantitatively investigate the waterflooding direction by injection/production rates. A new model—injection well with waterflood-induced fracture (IWWIF)—is proposed to characterize the abnormal BHP behaviors considering the properties variation (shrinking fracture length and decreasing fracture conductivity) of WIFs during the falloff period.
Compared with an individual method, the ITD (which is the abbreviation of WIF identification, formation testing, and dynamic production analysis) work flow is developed to obtain a comprehensive and deep understanding of waterflooding performance. The main emphasis of this study is to integrate different approaches to address the key uncertainties rather than analyze each data source individually. On the basis of the results obtained by this work flow, the operators can make a more-proactive and -reasonable decision on waterflooding management. The work flow proposed in this paper gives a useful guidance in short- and long-term waterflooding management in tight reservoirs.
Theoretical Study of Tool-Face Disorientation Mechanisms During Slide Drilling and Correction by Surface-Rotation Pulses
Authors: Wang Xueying , Ni Hongjian , Wang Ruihe , Wang Peng , Zhang Lei 
Published: October 2018

Summary
Tool-face control is an important issue when drilling directional wells with steerable motors. Although extensive knowledge about tool-face orientation is available, the mechanisms of tool-face disorientation during slide drilling are not completely understood. Surface-rotation pulses can correct tool-face orientation (Maidla and Haci 2004), but the underlying mechanism, in our view, remains unclear. This paper proposes a drillstring model to analyze the mechanisms underlying tool-face disorientation and correction.
Our drillstring model is based on the finite rigid-body assumption with a mixed friction model that incorporates Stribeck's friction curve. The simulation results indicate that tool-face hysteresis caused by the difference in the higher loading rate and lower unloading rate of reactive torque is an essential factor in tool-face disorientation. In addition, a harder formation is more prone to inducing tool-face disorder. The process of tool-face correction can be divided into three stages, and the position of the vanishing point of reactive torque determines the effectiveness of the surface-rotation pulse. The tool face turns clockwise only if the applied rotation pulse drives the vanishing point of reactive torque downward to the bit.
The simulation results and analysis are useful for understanding drillstring behavior during slide drilling and further improving the efficiency of tool-face control.
Overview of Industry Advancements in Environmental Awareness
Authors: Haut Richard , Wilcox Andra , Williams Tom , Burnett David 
Published: October 2018

Abstract
For the past fifteen years, industry, academia, government, environmental organizations and other stakeholders have worked together in a collaborative program to provide unbiased science to address environmental and societal issues associated with oil and gas activities. The research team has performed over 40 field trials related to land, water and emissions measurements. Case studies and specific examples on advancements in technologies and processes that have addressed land, emissions, water, stakeholder engagement, and other aspects are discussed. Also discussed is internal progress within industry to ensure that the workforce develops a culture of environmental awareness. Evolvement, aided by this collaborative effort, has been substantial. New technology developed has reduced land impacts through extended reach and horizontal drilling techniques, implementing new, energy-efficient rigs, and improving logistics coordination. Noise and lighting have also been addressed. Emissions have been reduced throughout drilling, completion and production operations through reduced drilling times, electrification of various processes, and flaring reduction. Operators have increased the recycling and use of produced water throughout completion operations and are implementing voluntary water conservation efforts. Public engagement by operators has increased acknowledging that stakeholder engagement is an important aspect of how to address environmental concerns. The team has developed novel methods, for example the development of virtual sites using gaming software, to enable stakeholders to become aware of the importance that industry places on addressing environmental aspects. How industry has successfully communicated advances in environmental stewardship is also discussed.
Successful Hydraulic Fracturing Techniques in Shallow Unconsolidated Heavy Oil Sandstones Part 2: Multifracturing Job Performance
Authors: Zagrebelnyy Evgeniy , Martynov Mikhail , Konopelko Alexey , Kazakov Evgeny 
Published: October 2018

Abstract
There is not enough experience of hydraulic fracturing on unconsolidated low-temperature shallow formations, similar to the main development site of the East Messoyakhskoye field - PK1-3, was found in Russia. Test fracturing was performed on directional and vertical wells in the pilot works in 2017 and the main conclusions were drawn:Approve technological capability of hydraulic fracturing on unconsolidated and high-permeability heavy oil reservoirApprove creating traditional vertical fracture by geophysical methods and by the results of productionValue of fracture height by different methods of mapping fracture geometry are semi-comparable, which makes it possible to estimate the averaged value of each parameterPerformed complex of geophysics logging allows to estimate in technological efficiency of hydraulic fracturingPerformed complex of laboratory studies of various chemical compound hydraulic fracturing fluids on the core material made it possible to select the optimal compound with minimal negative impact on the formationStep-by-step method increase of the aggressiveness of the treatment designs allowed the accident-free implementation of pilot works and estimate of possible aggressiveness to tip screen out (TSO)The productivity gains resulting from the development and operation of the wells after the fracturing allow to adapt the result to the MHF in horizontal wells with the expected productivity gain of 40%Limite fracture height growth is achieved by planning the optimal injection design, but it is not always possible. If gas-oil contact is near, it is difficult to control the geometry of the fracture, which led to the limitation of replicating the fracturing in water-oil zones without gas cap.
Ahead of the Bit Pore Pressure Prediction under Centroid Effect Conditions Using Express Seismic Processing Results for Exploration Drilling in the Caspian Sea
Authors: Smirnov Nikolay , Kerusov Igor , Aristarkhov Anton , Sokolova Maria , Evmenov Nikolay 
Published: October 2018

Abstract
For the offshore prospecting and appraisal well drilling optimization, an approach was proposed, included Pore Pressure prediction based on 2D processing of a seismic surface data. This approach was used for timely detection of sharp changes in Pore Pressure with depth, under expected «centroid» effect for a well construction in the waters of the Caspian Sea.
At the initial stage, an acoustic inversion of 2D seismic data wascarried out. Based on the obtained acoustic impedance section and seismic velocities, after a deep migration, Pore Pressure forecast was conducted for the well area. Pore Pressure was restored for the offset well and relations between effective stresses and seismic inversions results were identified for different facies. Together with the geomechanical support, regular velocity-depth model updating process was realized, involving log and well data from drilled section.
Using the velocity-depth model, updating process and continuous support, Pore Pressure forecast was successfully implemented in the intervals with sharp pressure variations. Bottom-hole updates were carried out in the critical further drilling intervals using updated formation velocities and seismic attributes, to the depth of next drilling section. In real time, the pronounced regional centroid effect was confirmed and successfully passed. Directly during the drilling, casing depths were corrected, mud weight values and equivalent circulation densities were controlled in safe ranges. In this work, regional centroid effect was predicted and verified for the Caspian Sea area.
The completed project demonstrates the successful application of a process involving tomographic update of velocity-depth model and continuous Pore Pressure forecast for optimization and increasing offshore prospect well drilling safety. This approach is critical for successful well construction under centroid effect, particularly, in the Caspian Sea area.