bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunohistochemical Evaluation of CD31 and D2-40, Expression in Oral Squamous Cell Carcinoma
Authors: Ibrahim Amr Mohamed , Alqalshy Emad , Abdel-Hafiz Ahmed Abdel-Shakour , El-Rahman Kamal Abd , Alazzazi Magdy , Omar Mohamed Refaat
Published: March 2022

(1) Background: The present study was carried out to provide new information about the relation between angiogenesis, tumor stage Oral squamous cell carcinoma (OSCC); (2) Materials and methods: Thirty formalin-fixed paraffin embedded blocks were used, 10 of them were previously diagnosed as well differentiated OSCC, 10 moderate differentiated OSCC and 10 poorly differentiated OSCC. To determine the expression of CD31 and D2-40 proteins, streptavidin-biotin immunoperoxidase staining technique was used. The areas with the most vascular density (hot spots) were determined. The stained vessels were counted independently in intratumoral and peritumoral stroma in five areas of hot spot at ×400 magnification; (3) Results: Immunohistochemical staining using CD 31 protein showed that CD31-positive vessels in the peritumoral and intratumoral stroma subjacent to the malignant invading nests which was recorded highest values in poor differentiated OSSC followed by moderate differentiated OSSC then well differentiated OSSC. D2-40 expression was positive in lymphatic vessel in the peritumoral and intratumoral stroma subjacent to the malignant invading nests. Poorly differentiated OSSC tissue sections recorded the highest vessels count followed by moderate differentiated OSSC then well differentiated OSSC. There was statistically significant difference found between the three studied groups regarding CD31 and D2-40 levels. Also there was statistically significant positive correlation found between CD31 level and D2-40 level and vice versa; (4) Conclusion: CD31 and D2-40 are related to stage of OSCC and are consistent with angiogenesis in tumor progression.
Residual Effect of Bentonite-Humic Acid Amendment on Soil Health and Crop Performance 4-5 Years After Initial Application in a Dryland Ecosystem
Authors: Ma Bin , Ma Bao-Luo , McLaughlin Neil B. , Li Ming , Liu Jinghui
Published: March 2022

Degraded soils causing from natural and human affects are universal in arid and semi-arid regions all over the world. Bentonite and humic acid (BHA) are increasingly being tested to remediate these degraded lands with potential benefits on crop production and soil health. The objective of this paper was to determine the residual effects four to five years after a one-time BHA application at six rates on (i) dynamic changes in soil properties, and (ii) oat crop productivity parameters, in a dryland farming ecosystem. With increasing rates of one-time BHA application, soil profile water storage displayed a piecewise linear increase plus plateau, whereas soil electrical conductivity, pH and bulk density were all reduced significantly (P < 0.05) in the 0-20 cm and 20-60 cm layers. The improved soil environments gave rise to an increased activity of soil enzymes urease, invertase and catalase that respectively reached the peak values of 97%, 37% and 32% at the rates of 21 to 24 Mg BHA ha-1. These conversely boosted soil nutrient turnover, leading to a 40% higher soil available P. Compared with the control treatment, application of BHA at the estimated optimum rate (roughly 24 Mg ha-1) increased grain yield by 20%, protein yield by 62%, water use efficiency by 41%, and partial factor productivity of N by 20%. Results of this study showed for the first time that a one-time BHA application would be a new and effective strategy to combat land degradation, drought, and promote a sustainable soil micro-ecological environment in dryland agroecosystem under a varying climate scenario.
Biological Activity of Propolis: An Update
Authors: Benhanifia Mokhtar , SOLTANI Amina
Published: March 2022

Antibiotic resistance was described soon discovery of penicillin by Fleming. In recent years, there has been increasing research interest in the development of alternatives to address this problem. Natural products, mainly, have long been considered as sources of drugs, and a great part of pharmaceuticals available in modern medicine are directly or indirectly derived from natural sources. propolis been used to treat human diseases since ancient times, propolis, is a natural resinous mixture produced by honeybees (Apis mellifera) from collected parts of plants, he is increasingly recognized by their wide range of biological and pharmacological properties, As anti- infective agent, combination synergy with standard antibiotics could be very promising alternative strategy
Analytical Sensitivity of Five SARS-CoV-2 Rapid Antigen Tests for Omicron Versus Delta Variant
Authors: Bayart Jean-Louis , Degosserie Jonathan , Favresse Julien , Gillot Constant , Didembourg Marie , Djokoto Happy Phanio , Verbelen Valérie , Roussel Gatien , Maschietto Celine , Mullier François , Dogné Jean-Michel , Douxfils Jonathan
Published: March 2022

Rapid antigen detection tests (RAD) are commonly used for the diagnosis of SARS-CoV-2 infections. However, with the continuous emergence of new variants of concern (VOC) presenting various mutations potentially affecting the nucleocapsid protein, the analytical performances of these assays should be frequently reevaluated. One-hundred and twenty samples were selected and tested with both RT-qPCR and five commercial RAD commonly sold in Belgian pharmacies. Of these, direct whole genome sequencing identified the strains present in 116 samples, of which 70 were Delta and 46 were Omicron. Sensitivity across a wide range of Ct values (13.5 to 35.7; median = 21.3) were comparable and ranged from 70.0% to 77.1% for Delta strains and from 69.6% to 78.3% for Omicron strains. When taking swabs with a low viral load (Ct > 25), poor performances were observed for the Delta strains (20.0 to 40.0%) and, even more so, for Omicron strains (0.0 to 23.1%). Two devices failed to detect all samples (n = 13) containing Omicron strains with a low viral load. The poor performance observed with low viral loads is an important limitation of RAD, which is not sufficiently highlighted in the instruction for use of these devices.
Monitoring Farmed Fish Welfare by Measurement of Cortisol as Stress Marker in Fish Feces by Liquid Chromatography Coupled with Tandem Mass Spectrometry
Authors: Meling Vanessa Andrea , Berge Kjetil , Knudsen David Lausten , Rønning Per Ola , Brede Cato
Published: March 2022

The aquaculture industry has become a sustainable provider of food to humans. Remaining challenges include disease issues, as well as ethical concerns for discomfort and stress among farmed fish. There is a need for reliable biomarkers to monitor welfare in fish, and the stress hormone cortisol has been suggested as a good candidate. This study presents a novel method for measurement of cortisol in fish feces based on enzymatic hydrolysis, liquid-liquid extraction, derivatization, and finally instrumental analysis by liquid chromatography coupled with tandem mass spectrometry. Hydrolysis and extraction conditions were optimized. Cortisol appeared to be mostly conjugated to sulfate and less conjugated to glucuronic acid in the studied samples of feces from farmed Atlantic salmon. The method was suitable for quantification of cortisol after enzymatic deconjugation by either combined glucuronidase and sulfatase activity, or by glucuronidase activity alone. The limit of detection was 0.15 ng/g and the limit of quantification was 0.34 ng/g, and the method was linear (R2>0.997) up to 380 ng/g, for measurement of cortisol in wet feces. Method repeatability and intermediate precision were acceptable, both with a CV of 11%. Stress level was high in fish released into seawater, and significantly reduced after eight days.
Development of a Novel Anti-CD44 Monoclonal Antibody C44Mab-46 for Multiple Applications against Esophageal Squamous Cell Carcinomas
Authors: Goto Nohara , Suzuki Hiroyuki , Tanaka Tomohiro , Asano Teizo , Kaneko Mika K. , Kato Yukinari
Published: March 2022

CD44 is a cell surface glycoprotein, which is widely expressed on normal and cancer cells. CD44 is involved in cell adhesion, migration, proliferation, survival, stemness, and chemo-resistance. Therefore, CD44 is thought to be a promising target for cancer diagnosis and therapy. In this study, we established anti-CD44 monoclonal antibodies (mAbs) by immunizing mice with CD44v3-10 ectodomain and screening using enzyme-linked immunosorbent assay. We then characterized them using flow cytometry, western blotting, and immunohistochemistry. One of the established clones (C44Mab-46; IgG1, kappa) reacted with CD44s-overexpressed Chinese hamster ovary-K1 cells (CHO/CD44s) or esophageal squamous cell carcinoma (ESCC) cell lines (KYSE70 and KYSE770). The KD of C44Mab-46 for CHO/CD44s, KYSE70, and KYSE770 was 1.1×10-8 M, 4.9×10-8 M, and 4.1×10-8 M, respectively. C44Mab-46 detected CD44s of CHO/CD44s and KYSE70, and CD44v of KYSE770 in western blot analysis. Furthermore, C44Mab-46 strongly stained esophageal squamous carcinoma cells in immunohistochemistry using formalin-fixed paraffin-embedded ESCC tissues. Taken together, C44Mab-46 is very useful for detecting CD44 in various applications.
Initiation of a “Lost” Large River on the East Asia Margin in the Middle Eocene
Authors: Fu Xiaowei , Yang Rong , Zhu Weilin , Yang Shouye , Geng Jianhua , Zhang Luyao
Published: March 2022

The forming of large rivers are the integral consequences of the deep earth process and the surface. In contrast to the hot topics for rivers related to orogenic domains, rift-related large rivers are largely ignored especially in deep time studies. The Cenozoic East Asia margin provides very good opportunity to observe this kind of rivers. It has been believed that basin-and-swell physiography dominated the East Asia margin and impeded the forming of large rives in the early Cenozoic. In this paper, we combined provenance analysis of East China Sea Basin, where is a crucial place to trace the river evolution in East Asia margin, and regional geologic constraints to reveal drainage reorganizations. Detrital zircon U-Pb ages from the Early Eocene sediments of the East China Sea Basin are firstly reported. Our results together with literature data demonstrate that regional provenance changes occurred at the middle Eocene from one singe age peak at ~110 Ma of proximal sources to multiple age spectrum derived from far inland. Source to sink analysis indicated that the North China Block and Korea Peninsular provided the most detritus. Sedimentation and tectonic features of rift basins in the potential source areas indicated that rivers flowed into Bohai Basin and Jianghan Basin cannot provide terrigenous clasts for the lower reaches in the Eocene. Contrastingly, the dominantly fluvial sediments across the Subei-South Yellow Sea Basin suggested external river system and a bypassing region since the middle Eocene, coinciding with provenance change in ECSB. All these demonstrated that a large river (East Asia River) established in east Asia margin in the middle Eocene and flowed southwestward approximately 1500km to the sea in southern ECSB. This river might last to the middle Miocene. The deep earth processes driven by Izanagi-Pacific ridge subduction resulted in the overfilled stage of Subei-South Yellow Sea Basin and the post-rift subsidence in west depression of ECSB, and thus facilitated the initiation of the EAR. Our finding shed new light on the evolving landscape in East Asia and showed how subduction of deep earth process controlled the initiation of rift-related large rivers.
Congenital Disorders of the Pediatric Thumb
Authors: Nguyen Jenny Lee , Ho Christine A.
Published: March 2022

» Surgical timing for pediatric trigger thumb treatment is controversial for numerous reasons including the potential for spontaneous resolution, the possibility of bilateral involvement, and anesthesia concerns regarding the developing brain. Hence, a reasonable approach is to delay the surgical procedure until the patient is ≥3 years of age.

» Preaxial polydactyly is usually unilateral and sporadic, with the most common reconstruction method consisting of excision of the diminutive thumb with preservation and soft-tissue reconstruction of the dominant thumb. The surgical procedure is typically performed around the patient age of 1 year to decrease the risks of anesthesia but allow reconstruction prior to the development of a tip-to-tip pinch.

» Triphalangeal thumb and thumb hypoplasia are often found in the setting of systemic anomalies such as Holt-Oram syndrome, thrombocytopenia absent radius syndrome, Fanconi anemia, VACTERL (vertebral anomalies, anal atresia, cardiac anomalies, tracheoesophageal fistula, renal defects, and limb anomalies), and/or Blackfan-Diamond anemia. As such, patients should receive adequate workup for these entities. A surgical procedure should be performed only once patients have been medically cleared.

» The status of the carpometacarpal joint in thumb hypoplasia determines whether reconstruction with first web space deepening, collateral ligament stabilization, and opponensplasty compared with index pollicization is performed.
Using Forms Quizzes to Enhance Students’ Motivation in Language Learning at a Japanese University
Authors: Kita Yoko
Published: March 2022

This study explores the effective utilization of the online program Forms via smartphones to enrich the classroom experience for both students and teachers in two prep classes for the standardized English Test, Eiken. The instructor used Forms to create, distribute, collect, and analyze surveys and quizzes. Students' attitudes toward English and their motivation to learn the language using these tools were examined. Via smartphones, they were given review quizzes that had game-like elements and that gave feedback in real time. Surveys investigating the degree of confidence in learning, the review quizzes, and smartphone usage were also distributed to their smartphones. The results indicate improvement in attitude towards English in general and enhanced confidence.
The Indigenous Poetry of Resistance by the Colombian Poet Fredy Chikangana: A Transitivity Systemic Analysis
Authors: Linares Sthephanny Moncada , Zhi-Ying Xin
Published: March 2022

The emergence of Indigenous poetry to the public domain has represented a milestone in their struggle to voice their communities' past and present experiences despite the ongoing ostracizing discourses from societies as the ones residing in Indo-America. In this sense, the present paper will offer an analysis of selected poetry by the Colombian indigenous poet Fredy Chikangana in the light of the transitivity system informed by the Systemic Functional Linguistics theory to unveil their experiential meaning construal. To attain this goal, a descriptive quantitative and qualitative research method approach was applied through which the different process types, participants, and circumstances arising from the corpus were systematically identified, calculated, and analyzed. Findings indicated that among the six transitivity process types, the material processes (47%) dominated his poems, followed by the relational realizations (27%) whereas the verbal, behavioral, existential, and mental processes were relatively low altogether, representing an overall occurrence of 26%. This reveals that the author’s primary goal was to employ poetry as an agentive act of resistance that originated from the context of the situation in which his Yanakuna community has been and is immersed.
THE ROLE OF PLS FINANCING ON ECONOMIC GROWTH: INDONESIAN CASE
Authors: Masrizal Masrizal , Trianto Budi
Published: March 2022

This paper investigates the role of PLS financing and non-PLS financing of Islamic banks in supporting the real sector for the case of Indonesia using monthly data from January 2009 to December 2018. Applying the ARDL approach to model their long-run and short-run relations, we find positive contribution of the PLS financing scheme to Indonesia's economic growth. Comparing the PLS and non-PLS financing, we note that the PLS financing has a larger impact on growth, both in the long run and short run. Accordingly, for Islamic finance to have larger growth impact, concrete steps and initiatives must be put in place to increase Islamic financing based on PLS arrangements.
Drilling Hard Abrasive Rock Formations with Differential Hydraulic Hammers: Dynamic Modeling of Drillstring Vibrations for ROP Optimization
Authors: Zhang Yifan , Yan Zeyu , Ashok Pradeepkumar , Chen Dongmei , van Oort Eric
Published: March 2022

In deep oil, gas, and geothermal well construction, percussion drilling is sometimes used to improve rate of penetration (ROP) and promote drilling efficiency when breaking hard abrasive rocks (with a uniaxial compressive strength (UCS) > 25 kpsi). Down-the-hole (DTH) differential pressure hydraulic hammers can be used to convert the hydraulic energy of the drilling mud into the percussion energy necessary for rock destruction. The appeal of using DTH hammers for deep hard rock drilling is that this is a highly mature, low-cost, and proven technology. Lacking, however, is a good model to describe mud hammer operation, allowing mud hammer parameters to be tuned for ROP optimization in hard rock environments.

In this study, bond graph models are used to investigate the hydraulic and mechanical dynamics of typical DTH hammer stroking cycles. The Colebrook-White equation is used to derive the Darcy-Weisbach friction factor for pressure loss caused by the turbulent flow between hammer chambers. The interactions between the hammer, the bit, and the formation are represented by three mass-spring mechanical systems with various degrees-of-freedoms (DOFs). Rock breaking is modeled using an anisotropic non-linear spring, which can represent the depth of the penetration of the hammer's indenters into the rock. This spring model also allows for seamless integration with the system model.

Dynamic percussion drilling behavior is simulated for various rock stiffness values while varying hammer parameters, such as input hydraulic pressure and piston-bit mass ratio. The simulation results provide estimations of both ROP and system energy transfer efficiency (ETE) expected for given hard rock drilling scenarios. The developed model can be used to optimize mud hammer parameters, which in turn will benefit ROP optimization in hard rock environments encountered while drilling deep oil and gas or geothermal wells.
Impact of Top Drive Torque Limit on Downhole Vibration Failures of Rotary Shouldered Connections
Authors: Petti Grant , Zheng Nanjiu , Koneti Srinivasa
Published: March 2022

Downhole separation of rotary shouldered connections in drill strings cause immense financial loss to oil and gas operators. Unfortunately, there seems to be an increasing trend in these downhole failures, particularly in deep water operations where the surface torque is limited by a top drive setting below the actual makeup torque of the drill pipe connections. This paper is intended to address the potential impact of the torque-limit setting at the surface on downhole torsional vibrations along the drill string when the operational torque approaches or exceeds that top-drive torque limit. The paper also discusses metallurgical testing methods that were used to identify the signatures of this failure type from multiple case studies.

The study uses a simplified analytical vibration model to evaluate the downhole dynamic torque along the drill pipe string and its dependence on the operation parameters, particularly top drive rotary speed. By applying the initial conditions directly correlated to failure cases, time-dependence of downhole drill string torque is calculated and compared to the recorded drilling data.

The vibration modeling process using simplified analytical models correlates well with the overtorque events in the failure cases modeled. The results also indicate that under certain circumstances downhole dynamic torque in the drill string could potentially be much higher than the top-drive torque limit setting at the surface. The metallurgical testing evidence provides support for the dynamic torque models in that damages were seen in the same patterns as predicted by the modeling. This modeling process, then, can be used to understand vibration problems in the drill string and correct for them by changing the top drive torque-limit settings and the rotary speeds.
MPD Cement Squeeze – The Advantage of Using Managed Pressure Drilling to Strip in Hole, Perform a Cement Squeeze and Confirm the Loss Zone is Isolated
Authors: Hester Clayton , Hammad Mohamed , Hollman Landon , Gabaldon Oscar , Hernandez Julian , Hernandez Angel
Published: March 2022

The objective of this paper is to show the advantage of utilizing Surface Back Pressure (SBP) to control the gain and loss of mud while stripping in/out of the well, during recovery from a high mud loss event. The use of the MPD system assisted in performing a cement squeeze while minimizing the risk of stuck pipe, and subsequently confirming if the loss zone has been isolated. In the Shafag Asiman field of the Caspian Sea, a Managed Pressure Drilling (MPD) system was installed on a semi-submersible rig to drill an exploration well with uncertain pore pressure and fracture gradient window. While drilling the 14 3/4 × 17 1/2 in. section, losses were initially detected by the MPD systems Coriolis meter. Once total losses were confirmed, the decision was made to cement the loss zone and perform an open hole sidetrack.

This paper provides a summary of how the MPD technology was used to assist in managing gains/losses during a post mud loss event, and its vital role in minimizing the risk of stuck pipe when performing the cement squeezes to isolate the loss zone and subsequently balanced plug which enabled a successful open hole sidetrack, and minimized the number of operational days and carbon emissions.
Shaped Cutter Performance Optimization Through Advanced Drilling Simulations
Authors: Russell S. Craig , Duffy Stephen , Matthews Oliver
Published: March 2022

Historically polycrystalline diamond compact cutters have consisted of a planar cutting face on a cylindrical diamond table. For decades industry has been aware of the potential drilling performance gains from forming these cylindrical cutters into other geometrical shapes. These early generation shaped cutters did not gain traction due to limitations in diamond technology, and high manufacturing costs associated with shaping the cutters. Recently PDC drill bits with shaped cutter designs are becoming more prolific in worldwide drilling applications. Often, the novelty in the design of the cutter shapes is enticing enough to merit opportunities for field runs. However, without an informed understanding of shaped cutter behaviors, there is risk of diminished drilling performance if the cutter shapes are not applied properly to the bit and application. The objective of this paper is to develop methods to evaluate two critical behaviors for shaped PDC cutter designs, overload integrity and aggressivity, and apply these methods to a full bit drilling model.

The cutter overload integrity characterization methods are developed using finite element analysis and the aggressivity characterization is based on high pressure visual single point cutter laboratory test data. The information is fed into a full bit drilling numerical model to predict bit performance and ability to avoid cutter breakage in a simulated drilling environment, accounting for factors such as lithology, interbedded transitions, bottom hole assembly type, and operating parameters. The models enable optimization of shaped cutter design and fit for purpose cutter selection.

The full bit model is tested and validated against field runs. Case studies include interbedded drilling in the Haynesville and Permian Basins. In both applications, bits were run with different shaped cutter designs, using drilling performance and dull photos to compare to the model outputs. ROP gains of 35% were seen in the Haynesville application, while the cutter survival rate more than doubled in the Permian application by using optimally selected shaped cutters.

The methods presented in this paper provide new pathways for shaped cutter design and selection. Digital tools are demonstrated to perform the multi-faceted analysis efficiently for pre-well planning and post-run analysis.
Building and Deploying an Open Plug-and-Play Solution for Supervisory Well Construction Automation
Authors: Grøtte Arnfinn , Marck Julien , Parak Mahdi , Laing Moray , Kvammen Oddbjørn
Published: March 2022

Oil and gas operators continue to seek better ways to unlock value from operational data and drive consistent, predictable performance while mitigating risk on a well-to-well basis. This paper describes how a wellsite Edgecomputing solution was developed to connect and orchestrate the well-activity plan with wellsite advisory systems, provide unified instructions for drilling automation systems, improve the human-to-system interface, and connect cloud-based data lakes to real-time wellsite operations. Crucially, the system leverages open technologies and frameworks to expand options and provide a low-barrier entry point to automation for all vendors. In this new environment, multiple engineering applications can execute in parallel in a distributed microservice-based system ensuring the most pertinent models are continuously leveraged and anchored to the current operational situation. The engineering outputs are then orchestrated against current and future operational context to manage drilling limiters while anticipating and mitigating possible dysfunctions and inefficiencies. As automation has become a mainstream technology in well construction, there is a need for open platforms that integrate both well-activity plans and engineering systems into automated decision-making rig systems. This paper provides details on how this gap has been closed through a vendor-agnostic platform, which aggregates high-frequency, low-latency real-time data with well-planning information and hybrid data-driven models to provide closed-loop control and context-based decision making that interoperates directly with surface and subsurface drilling-automation systems.
Application of Vibration Mitigation Technology to Improve Performance and Reliability in the D.J. Basin
Authors: Marland Christopher , Gonzalez Duane , Koy James
Published: March 2022

Vibration and drilling dysfunction continue to be a limiting factor to drilling performance. Minimizing vibration lowers the failure rate of downhole tools from short term catastrophic failures to longer term fatigue failures. Minimizing dysfunction reduces bit and BHA damage which reduces bit trips and improves performance as optimal operating parameters can be applied for longer. In onshore operations, short well cycle times strain logistics and asset availability. Rerunning assets, such as rotary steerable and MWD tools, is a significant cost saving to both the operator and service company. Mitigating vibration can be achieved through BHA design, bit design, and manipulating drilling parameters. However, these can be uneconomical, because they require a lot of trial and error, along with, multiple combinations and iterations. Using downhole vibration mitigation tools can be a more cost-effective method of reducing vibration while achieving economic drilling performance.

This example from the D.J. Basin, Colorado, used two different downhole vibration mitigation tools to try and reduce the magnitude of vibration, specifically, tangential vibration, which posed a higher risk of failure to the directional drilling tools. Four wells on a single pad were selected for the trial to ensure similar geology and well design. Four wells that had comparable geological and well profiles, were selected as offsets. The aim was to reduce vibration and successfully rerun the directional drilling tool on at least two consecutive wells, while maintaining the offset well's ROP.

The paper will outline the design of the two technologies and the results from each well. Changes in vibration magnitude will be explained and the effect on ROP. The paper will compare the four trial wells to the four offsets and contrast the performance of the two tools in the trial wells. The paper will also discuss mechanisms unaffected by the technology and how that provided insight into the interrelationship of vibration mechanisms.

During the technology evaluation process, it became apparent that the run history with vibration mitigation tools was relatively low for the D.J. Basin. Of the two technologies, only one had previous experience in the basin with less than 50 runs over the previous 10 years. This was the first application of this type of downhole technology for this operator in this basin. The results have identified vibration as a performance founder point and helped demonstrate the change in performance that can be achieved by reducing drilling dysfunction.
Development Methodology for Ultra-Lightweight Drilling Fluids Using Hollow Glass Beads
Authors: Kostov Nikolay , Penny Glenn , Rao Sai , Wu Qian , Gupta V. Paul
Published: March 2022

Lightweight drilling fluids are needed to drill depleted formations and can also be used to maximize drilling rates of penetration. This paper presents a methodology developed to design and test ultra-lightweight drilling fluids utilizing a high concentration of hollow glass beads (densities <5.5 lbm/gal). These fluids can be used as a simpler alternative to foam or air drilling in applications requiring densities in the 4-6.5 lbm/gal range.

As a starting point the field application requirements were developed which then were used to define a set of functional requirements for the hollow glass beads (HGB) fluid; tests and procedures for evaluating the performance against functional requirements were then developed. These included survival of the beads at downhole pressures and temperatures, survival of the beads under mechanical impact, formulation stability against hollow glass bead floatation, and rheological stability in addition to normal drilling fluid design requirements (e.g. compatibility & contamination testing). Selection of bead type and base oil were part of the development process. Several new lab tests were developed and conducted which allowed for assessing the performance and making adjustments until the functional requirements were met.

Several HGB drilling fluid formulations were successfully developed meeting all the functional requirements. Fluid densities as low as 4.6 lbm/gal were successfully tested; this is the lowest density hollow glass beads drilling fluid that we are aware of. Hollow glass bead survival at increased pressure and temperature was above 90% for pressures around 4000psi. In addition, the formulations show excellent stability with minimal glass bead floatation even at elevated temperatures. The mechanical survival of the glass beads was also studied in the lab and estimated to be over 90% in a typical well application. Rheological properties showed good stability with both pressure and temperature. Standard drilling fluid hydraulics software can be used for modeling the wellbore pressures.

The methodology described presents a systematic approach to developing ultra-lightweight HGB drilling fluids (below 5.5lbm/gal); these can be used in drilling applications where significantly lower densities below base oil densities are needed, especially as a simpler alternative to foamed fluids used in drilling depleted reservoirs (e.g. conventional depleted wells, drilling with MPD, mud cap drilling). The methodology also allows for determining the lower limit of densities that can be designed for a particular application, and can also be utilized for developing ultra-lightweight fluids for non-drilling applications.
New Methods for Improving Drilling Performance: The Power of Digital Workflows
Authors: Aguiar Romulo , Barreto Diogo , Tocantins João Pedro , Barr Alex , Lima Laura , Li Denis , Hemerly Adriano , Martins Guilherme , Lima Flank , Sortica Emanuel , Teixeira Paulo
Published: March 2022

After 10 years of Brazilian presalt exploration and development, the carbonate reservoirs continue to pose drilling challenges, leading to unwanted bottomhole assembly (BHA) trips due to severe shock and vibration, low rates of penetration (ROP), and premature drill-bit cutting structure damage. Today, industry efforts to improve the performance in the Brazilian presalt carbonates are driven by trial and error, which is very costly in the ultradeepwater drilling environment. The adoption of a collaborative mindset since 2012 between a service provider and operator with the desire to bring about a step change in drilling efficiency on the Brazilian presalt cluster enabled a systematic learning framework to capture, evaluate, and reuse knowledge from drilling dynamics, geological, and petrophysical aspects. The innovation of this work is the implementation of an improved, fully digital bit design workflow, integrating calibrated 4D dynamic simulation model and petrotechnical expertise from drilling engineering, geomechanics, geology, and petrophysics groups to continue to push the drilling performance envelope in the challenging Brazilian presalt application.
Pre-Drilled Liner Standoff Estimation for Mud Removal using Stiff-String Model
Authors: Esteva Milton , Donis Erickson , Miller Richard
Published: March 2022

Open-hole gravel pack (OHGP) completions rely on having a clean wellbore and fluid environment at the time of construction to achieve optimum productivity. Drilling mud removal is imperative to achieve this purpose. In OHGP designs where a pre-drilled liner (PDL) is utilized across the open-hole interval, centralization of such a PDL assembly is key to accomplishing wellbore cleanliness during displacement of the drilling mud to completion brine. Unfortunately, due to the need to maximize the area open to flow within the PDL, the liner centralization strategy is limited. Furthermore, an inner string is needed for effective mud displacement from the bottom of the PDL. The presence of the inner string adds complexity to the mechanical interaction with the PDL, demanding higher centralization performance.

In this study, PDL standoff is estimated using a stiff-string model. This model overcomes the limitations of the soft-string model as it accounts for the mechanics of pre-drilled holes, the bow-spring centralizer, and loads imparted by the inner string.
Enabling Foam Application in PMCD Using a Hydraulics Model
Authors: Rao Sai Sashankh , Mollica Juan , Wu Qian , Samdani Ganesh Arunkumar , Gupta Vishwas Paul
Published: March 2022

Pressurized Mud Cap Drilling (PMCD) requires use of an annulus fluid that is slightly underbalanced to the reservoir; the use of foam is proposed for low bottomhole pressure applications. Such an application requires a foam hydraulics model to guide the planning and operations as pressure management is key for PMCD. This paper presents the development of a novel 1-D steady state wellbore scale foam hydraulics tool and its application to a PMCD operation. User inputs include non-Newtonian rheology, PVT, solubility, temperature profile, pipe RPM, and reservoir pressure. The primary operational parameters are the gas/liquid rates at the surface. The density and pressure profile of foam in the wellbore is calculated to guide the formulation development and determine optimum operational parameters. The challenge is to develop a foam that can at the same time balance reservoir pressure (density design), be pumped at the desired downhole rates (for influx management) at permissible surface pressures (viscosity design), and is stable under wellbore pressures and temperatures (formulation design). These opposing requirements make the design an iterative process. Sample hydraulics results are presented for an example well and a sensitivity analysis is performed to demonstrate the effect that various operational and well parameters have on the hydraulics of a foam system. Both the pumps-on and pumps-off scenarios are studied. Additionally, a CFD analysis is performed to study the effect of drill pipe rotation in an eccentric annulus on friction pressure drop. A non-monotonic trend is observed due to the competing effects between the shear-thinning behavior (reduces viscosity) and turbulence (increases effective viscosity). The hydraulic model is verified by comparing against analytical solutions, an industry standard drilling software, experimental data, and CFD simulations. The paper demonstrates the importance of a foam hydraulics tool for a PMCD application and how it factors into the overall design of a foam system. It is shown to be a critical part of the foam formulation development, selection of density, rheology, gas/liquid ratio, and target pump rates and expected pressures.
Best Practices to Improve Accurate Time Stamping of Data at the Well Site
Authors: Annaiyappa Pradeep , Macpherson John , Cayeux Eric
Published: March 2022

Due to the nature of the drilling process, there are several companies collecting data at the rig. Each company's data acquisition system applies its own time stamp to the data. Subsequent aggregation of data, for example in a data lake, relies on synchronized time stamps applied to the different data sources in order to collate the data. Unfortunately, synchronized time stamping is rarely true. This paper documents the different sources or errors in time stamping of data and provides some best practices to help mitigate some of these causes.

There are many reasons for unsynchronized time stamping of data from different sources. It can be as simple as clock synchronization at the rig: each data providing or producing company has an independent clock. It can also be due to where the time stamp is applied: for example, at the data source or on data reception. Additionally, it can be due to how the time stamp is applied: at the start of the interval, the mid-point, or the end.

Many of the protocols used at the well site have a high latency, mud pulse or electro-magnetic (EM) telemetry, or even WITS (Wellsite Information Transfer Standard), where the actual acquisition time may vary significantly from the time stamp. Perhaps finally, time stamping of derived data is always problematic given the unsynchronized nature of data sources.

Synchronization of clocks within the data acquisition network is extremely important. The resolution of time synchronization depends on purpose: motion control for example demands high-resolution time keeping. However, for the purposes of local time stamping, synchronization to a Network Time Server with a resolution of one millisecond is sufficient. The issue is on agreeing on the common source, and agreeing on passage of the time signal through firewalls.

Time stamping is a more involved matter, calling for agreement on standards and a degree of metadata transparency. The paper describes in some detail sender versus receiver time stamping, the downhole to surface time-stamp chain, and time stamping of derived data.

Systems automation and interoperability at the rig site – allowing plug and play access to equipment and applications – rely on an agreed upon network synchronization scheme. Indeed, designing applications that must handle uncertain time adds considerable complexity and cost, not to mention the impact on reliability. This paper presents an ordered approach to a quite resolvable problem.
Modelling the Economic Impact of Spacing Uncertainty in Unconventional Long Laterals Due to Common Survey Practices
Authors: Cheng Katherina , Cosca Nicolas , Jose Minsu , Willerth Marc
Published: March 2022

Finding an optimal lateral spacing is crucial to maximizing the return on investment for unconventional assets. The estimates regarding these lateral spacings were made for various plays; however, in a general sense, they assumed that the wellbores were precisely drilled and surveyed (Bharali et. al., 2014; Lalehrokh & Bouma, 2014). Wellbore positions have potentially large uncertainties and recent studies demonstrate that these uncertainties are even larger than previously assumed (Love, et. al, 2020).This study combines the previous work completed on spacing uncertainty with a reservoir simulation model to better quantify the losses caused by positional uncertainty, while exploring the sensitivity of said losses in relation to the changing lateral length, well spacing and survey accuracy allowing for future optimal field development.

A previous method of simulating reservoir losses due to survey uncertainty, proposed by Maus & DeVerse (2016) and the major basins reservoir simulation using empirically derived positional uncertainty models generated by analyzing survey data from thousands of wells by Love et. Al., (2020) provided the framework for this study. The estimations for typical production losses due to survey uncertainty were produced from simulations and compared to similar simulations using industry standard error models. In all cases, a baseline simulation was run, estimating production losses observed on historical wells alongside additional simulations to determine the sensitivity of losses on future wells against lateral length (5,000 - 15,000 ft), lateral spacing (220 - 880 ft) and employed survey management techniques. The effect of estimated losses and deviations from expectations using standard error models were explored, including an analysis of average production losses, extreme events (such as maximum modeled production loss and number of lateral crossings), and the impact of uncertainty reduction techniques commonly employed through survey management.

After performing simulations using empirically derived well paths and uncertainty models, it was found that simulations using standard error models may have greatly underestimated recovery losses due to survey uncertainty. The empirical error-model simulations suggest that realized losses for common drilling scenarios may be up to 5% or more of expected production, a much higher value than the previously estimated value of 0.5 - 2% using standard error models by Maus and DeVerse. Simulations suggest that these losses can be reduced up to 80% using survey management techniques to improve the accuracy in wellbore positioning.

Up to present times, there has not been a quantitative look at how real drilling and survey practices employed in unconventionals impact field economics. This work synthesizes prior efforts to estimate the true surveying uncertainty and links it to an ultimate asset value.
Design of Carbon Capture and Sequestration CCS Wells
Authors: Ceyhan Ismail , Pilisi Nicolas , Suryanarayana P. V. , Krishnamurthy Ravi M.
Published: March 2022

This paper discusses a methodology for the design of wells in carbon capture and sequestration (CCS) projects. In addition to carbon dioxide (CO2) injection wells, CCS wells include observation or monitoring wells, as well as utility wells, which are used to reduce pressure by removing formation water.

The paper first outlines the differences between CCS wells and conventional oil and gas wells. These differences include much longer regulatory lifetimes, increasing pressure over well lifetimes, inherently corrosive environment, intermittent operation and large variation of CO2 injection stream properties depending on its impurities. These differences require a different approach to well design for CCS projects. A well design philosophy, which has been developed to address these differences, is presented. The paper outlines the material selection guidelines and tubular load cases. The design philosophy, material guidelines and load cases are illustrated through several example well designs.

For CCS wells, the design should start with the completion size required to achieve the desired CO2 injection rate, and progress outwards. Dual containment is essential; the second barrier must not only be designed for the corrosive environment, but the second barrier and its associated equipment must be periodically inspected or tested. All CCS wells, including injection, monitoring and utility wells, must be designed for potential CO2 exposure. Highest loads may be imposed during transient or upset operations, and may originate from changing thermal conditions. Cement integrity is essential to prevent undetected migration of stored CO2 out of the storage zones. Finally, it is necessary to have pre-prepared contingency plans to detect, shut-in, kill, repair and/or P&A failed wells.

The differences between CCS wells and conventional oil and gas wells require a different approach to well design. If CCS wells were to be designed using conventional methods, the wells might fail to maintain their integrity, thus resulting in the failure to contain injected CO2 in the sequestration zone.
Updating the Dull Grading System
Authors: Alam Mahabub , Case Spencer , Hussain Junaid
Published: March 2022

The IADC standardized dull grading system was developed for both roller cone bits and fixed cutter bits in 1987 and last updated in 1992. In the meantime, fixed cutter bits have taken most of the market share from roller cone bits; drilling technologies, tools, and features changed significantly. The current IADC dull grading system is unable to capture new information and has issues with consistency, accuracy, and precision.

A detailed analysis has been conducted using historically collected dull grading data that are available in the Ulterra database to understand the usefulness of the items in each column of the IADC dull grading system. The study surveyed people in different disciplines including sales, engineering, manufacturing, and marketing within the company to develop a novel updated dull grading system to make it useful across the board. The per-formance of the dull grading system is measured in terms of consistency, accuracy, precision, and compatibility with existing drill bits. The study evaluated and updated the structure (the way 8 columns are being divided), scal-ing of the worn cutters, and the items of the columns of the dull grading system.

The historic data analysis results showed that some of the items in the current dull grading system are ob-solete or rarely used. The survey of the study is designed to assess the performance of the current system and compare it with the proposed system. The survey analysis results demonstrate that the proposed dull grading system is more user-friendly, consistent, accurate, and precise. The proposed dull grading system is developed focus-ing on fixed cutter bits as those hold over 90% of the market share. However, the grading system applies to roller cone bits and the hybrid of fixed and roller cone bits. A few worn fixed cutter bits are graded and shown as exam-ples using the proposed grading system. A novel updated dull grading system has been proposed, where the structure of the system, requested in-formation, and the method of data collection for a dull bit is updated. Considering the advancement of automation and digitization, digitizing the dull grading system would be the most useful goal. The proposed updated dull grading system would be a step towards digitization.