bluuebunny/crossref_metadata_2025 huggingface dataset:
Single Nucleotide Polymorphism of Partial GDF9 Gene in Three Local Goat of Indonesia Compare with Several Goat in Asia
Authors: Chairunissa Fatimah Az Zahra , Bintara Sigit , Hartatik Tety
Published: February 2022

The GDF9 gene is a gene that affects the maturation of oocytes. GDF9 is expressed in oocytes and granulosa cell, it can stimulate granulose cell proliferation and regulate cumulus cell function from pre-ovulation to ovulation. The GDF9 gene is associated with an increase in the ovulation rate and litter size in animals. This study aims to determine the kinship relationship of local goats compared to goats in Asia on prolific traits and to determine the restriction mapping of the GDF9 gene in goats based on the different SNP locations. The local goat comes from the Bligon goat, Kacang goat and Kejobong goats which is compared to the GenBank data (EF446168, EU883989 and KY780296). GDF9 sequences were analyzed using BioEdit and sequencing results to identify Single Nucleotide Polymorphism (SNP) and using NEBCutter V2 to determine the restriction enzyme which recognized the sequence around SNP. The result shows that three variations of SNP were found in exon 2 (g.3615T>C, g.3760T>C and g.3855A>C). Identification of SNP position found 1 SNP position identified by restriction enzyme at g.3855A> C. The identified restriction enzyme is HpaII and MspI. The results of this study are expected to provide genetic information that will be used for further research on the relationship between GDF9 gene polymorphisms to animal prolific.
The Effect of Flushing Premating with Spirulina Platensis Supplementation on Ewes Postpartum Estrus
Authors: Sarvinda Diahanvika Tri , Bintara Sigit , Budisatria I Gede Suparta , Kustantinah Kustantinah , Baliarti Endang
Published: February 2022

Lactating ewes require high nutrients for basic life requirements and milk production. If not fulfilled, it can have an impact on Negative Energy Balance (NEB) that reduces body weight, Body Condition Score (BCS), and extend the appearance of Postpartum Estrus (PPE). Premating flushing feed is an effort to improve ewe nutrients by adding high nutrition for preparation before mating so that after lambing and suckling, the ewe immediately estrus. This research aimed to evaluate the performance of ewes through premating flushing feeding. The research was conducted at Mendo Galak Farm, Sleman, Yogyakarta. Twenty ewes 2-3 years old with BCS 2-3 divided into two groups; the group with flushing treatment consisted of dried water spinach (Ipomoea reptans poir), concentrate feed with Spirulina sp. (14,92% crude protein, 60,28% total digestible nutrients), and the control group (PS) without Spirulina sp. (crude protein 11,82%, total digestible nutrients 53,20%). Flushing feed was given after a month postpartum as much as 3% dry matter of body weight. The recorded parameter was daily feed consumption, monthly body weight, BCS, and postpartum estrus. The data obtained were tested by an independent T-test with Statistical Product and Service Solution (SPPS ver. 22). The results showed the consumption and digestibility of CP, TDN, and ewe's ADG had a significant difference (P<0.05).  Postpartum estrus (PPE) of flushed ewes had no significant difference (P>0.05), 73.90±11.55 vs. 77.60±14.65 days, respectively. The conclusion was that flushing premating treatment with the addition of Spirulina platensis increased the nutrient intake and digestibility of CP, TDN, and ADG but had not shortened on postpartum estrus of lactating ewes.
The Quality of Buffalo Sperm Following Preservation Using Different Diluents and Sperm Concentrations
Authors: Yendraliza Yendraliza , Ridho Muhammad , Rodiallah Muhamad , Zumarni Zumarni
Published: February 2022

Artificial Insemination (AI) success depends on the quality of the frozen semen. The quality of the frozen semen of swamp buffalo in Indonesia is still low. The study was conducted to determine the quality of buffalo sperm following freezing using three different diluents and three different doses. The study used buffalo semen from the Tuah Sakato Artificial Insemination Center, Payakumbuh (n = 3). The semen collecting was carried out once a week for 10 weeks (replication). The research method used was 3x3 factorial  randomized block design. The first factor was diluent (Triladyl®, Andromed® and Tris egg- yolk) and the second factor was the dose of spermatozoa (10 and 15 and 20 x 106 sperm/ml). Data were analyzed using variant analysis, while the differences between treatments were tested by Duncan Multiple Range Test. The results showed that the plasma membrane integrity of buffalo sperm was found in Andromed® diluent, while tris egg-yolk diluent gave better motility, viability, plasma membrane integrity and recovery rate at a sperm concentration of 20 x106 sperm/mL compared to triladyl® diluent and a sperm concentration of 10 and 15 x106 sperm/mL. It was concluded that andromed® diluent and tris egg-yolk gave better motility, viability, plasma membrane integrity and recovery rate at a sperm concentration of 20 x106 sperm/mL compared to triladyl® diluent and a sperm concentration of 10 and 15 x106 sperm/mL. of Buffalo of sperm abnormalities not sicnificantly by the type of diluent but are influenced by sperm concentration.
Developing Strategy to Reduce the Mortality of Native Chicken using Qualitative Modeling
Authors: Ismoyowati Ismoyowati , Tugiyanti Elly , Indrasanti Diana , Setianto Novie Andri , Armelia Vony
Published: February 2022

Smallholder native chicken farming continues to face challenges that include simple farming management as well as ND and AI diseases that lead to decreased productivity and increased mortality rate. The aim of the study was to develop a strategy to reduce the mortality rate of native chickens in extensive and semi-intensive rearing systems. This study uses survey method with 78 extensive and 88 semi-intensive native chicken farmers as respondent. This study explores the disease incidence, illness treatment, mortality rate, as well as AI and ND antibody titers which then analyzed descriptively. System dynamic model using Ventana software (VENSIM) was used to identify the contributing factors to the mortality rate of native chicken in smallholder farming. The results showed that the common diseases among native chickens reared in semi-intensive and extensive farming are AI, ND, CRD, and pullorum, with a high rate of disease-specific mortality (>5%). Compared to native chickens in semi-intensive farming, those of in extensive farming showed a higher natural immunity against AI and ND. The qualitative modeling produced seven reinforcing loops and five balancing loops. Some challenges in developing native chicken farming were disease incidence due to lack of proper land and cage, the occurrence of selling unhealthy chickens, farmers opting out for poultry vaccination, high operational cost, lack of business motivation, limited knowledge on poultry management and health, lack of extension programs, and traditional management. We concluded that the rate of disease-specific mortality (ND and AI) remained high in native chickens reared both in extensive and semi-intensive farming. It takes an effort to improve farming management, vaccination, and the government’s contribution through extension programs to decrease disease incidence and mortality rate of native chickens.
The Effect of Protected Lemuru Fish Oil Supplementation on In Vivo Nutrient Digestibility and Sheep Blood Profile
Authors: Dewi Ratri Ratna , Kustantinah Kustantinah , Muhlisin Muhlisin
Published: February 2022

This research was intended to observe the effect of protected lemuru fish (Sardinella longiceps) oil for ruminants, especially for sheep. This study aimed to evaluate the digested nutrients and blood profile of sheep. This study was conducted in September-October 2020 in Dumbira Farm, Kalasan, Yogyakarta, using 12 sheep divided into 3 treatments with 4 replications each. Treatment P0 was Total Mixed Ration (TMR) without protected Lemuru fish oil (control), treatment P1 was TMR with 5% protected Lemuru fish oil, and treatment P2 was TMR with 10% protected Lemuru fish oil. The data were statistically analyzed using one way analysis of variance and continued with Duncan new Multiple Range Test for significant results. The results of this study indicated that the addition of 10% protected Lemuru fish oil in TMR feed had a significant effect (P<0,05) on the increased value of in vivo digestion of crude fiber and crude fat, but did not affect the digestibility of dry matter, organic matter, and protein. The addition of protected Lemuru fish oil did not cause hematological disorders showed by the blood profiles were in the normal range. In conclusion, protected lemuru fish oil supplementation had a favorable influence on the production performance without affecting blood profile of sheep.
To Determine the Effect of Using a Complete Feed Containing Protected Soybean Groats in the Production of Javanese Thin-Tailed Male Sheep Carcasses
Authors: Arif Yahya Nor , Isnaniyah Nurul Fatimah , Pramono Ahmad , Riyanto Joko
Published: February 2022

The present study aims to determine the impact of complete feed containing protected soybean meal on the production of male thin-tailed lamb carcasses. A total of 15 (23.43 ± 1.40 kg) 12 months old male Thin-Tailed Sheep (TTL) were given 3 treatments and 5 replicates in a completely randomized design. The ration consisted of complete feed and formaldehyde-protected soybean groat (PSG). The treatments includes 100% complete feed (F1), 90% complete feed + PSG 10% (F2), and 80% complete feed + PSG 20% (F3). Data were analyzed using ANOVA and differences between treatments were further tested using Duncan’s New Multiple Range Test. The results indicated that the use of PSG containing complete feed did not improve the characteristics of carcasses (weight and percentage of carcass components, half-cuts and commercial cuts of carcass, fleshing index and meat bone ratio) of male TTLs (P>0.05). However, differences were found  in the rib eye muscle area. The use of complete feed containing 20% PSM (F3) resulted the highest rib eye muscle area figure compared to those of F2 and F1 (35.17 vs 27.00 and 26.33; P<0.05). Our study revealed that the use of complete feed containing 20% protected soybean groat resulted in higher rib eye muscle area by 25.14% compared to those containing no protected soybean groat. However, no differences in carcass characteristics were found in view of weight and percentage of carcass components, half cut and commercial carcass, fleshing index and meat bone ration in thin-tailed sheep.
Pay (No) Attention to the Man Behind the Curtain: The Effects of Revealing Institutional Affiliation in a Consortial Chat Service
Authors: Barrett Kathryn , Pagotto Sabina
Published: February 2022

This study aims to understand how users within a library consortium perceive chat service provided by staff members who are unaffiliated with the user’s home library. The researchers examined 293 chat interactions from Ask a Librarian, a consortial virtual reference service provided to university libraries across Ontario, Canada. Chi-square tests of independence were performed to explore the relationship between user dissatisfaction and instances where the chat operator revealed a mismatch in institutional affiliation between the operator and the user. Moderating variables in the relationship were investigated, including user type, question type, and operator behaviors like transferring the chat, making a referral, revealing a lack of expertise, and saying no to the patron. The researchers found that when an operator revealed that they work at a different institution than the user, patrons are more likely to be dissatisfied if they are graduate students, if their question is research-related, if the operator does not offer to transfer the chat, and if the operator does not state that they lack expertise on the chat topic. These findings suggest that chat operators should be mindful of context and relationships when revealing information about their affiliation. Users may perceive operators from other institutions as lacking knowledge about their local library, or they may be confused or alienated when receiving “behind the scenes” information about staffing that they perceive as unnecessary. The researchers recommend emphasizing and strengthening the user’s relationship with their home library and local library staff.
Online Assessment Effect in EFL Classroom: An Investigation on Students and Teachers’ Perceptions
Authors: Fitriyah Ima , Jannah Miftahul
Published: March 2022

The teaching and learning process changed into an online during the COVID-19 outbreak, and thus online evaluation became a requirement. This research examines the positive and negative effects of online assessment on students’ learning behaviour and how teachers prepare their teaching. This case study research included the result of questionnaire from thirty IC students followed by interview with three EFL teachers in the Intensive English Course (IC) program and six IC program students in one of Islamic University in Kediri. The small survey indicated that students have positive attitude toward the administration of online assessment. Furthermore, the outcomes of open-ended interviews showed that there were four themes for beneficial effects, including enhancing flexibility in assessment, improving evaluation versatility, building teachers and students’ awareness of preparing evaluation and cultivating students’ autonomous learning abilities. On the other hand, three themes for negative effects emerged from the online assessment, including complication of evaluation administration, reduced interaction between teachers and students, and anxiety in English test. The effects emerge from how teachers and students view the drawbacks of the online assessment itself. Positive effects lead to students’ learning better are caused by lesson taken from conducting the test; however, the negatives should be treated as challenges that will improve the teaching and learning. Finally, both teachers and students are ready to face online assessment in the future.
POLICY RATES PASS-THROUGH IN INDONESIA’S DUAL BANKING SYSTEM: DOES BUSINESS CYCLE MATTER?
Authors: Triwibowo Sugeng , Oktaviani Defy , Ginanjar Adhitya , Ardiansyah Danu F.
Published: March 2022

This paper examines the pass-through of the policy rate to conventional and Islamic bank rates during the recessionary and expansionary episodes for the case of Indonesia. Applying an error-correction modelling to monthly data from June 2014 to April 2021, our findings confirm that the interest rate pass-through is sensitive to the business cycle for both conventional and Islamic banks. The policy rate pass-through to deposit rates is higher during the recession for both banking types. We also note that the lending rates of conventional banks fully adjust to the policy rate in the recessionary phase. The findings for Islamic financing rates are interesting. Namely, they tend to move inversely with the policy rates during the expansionary period. Meanwhile, depending on the rates, they are either over-responsive or less responsive during the recessionary phase. Finally, the degree of short-run adjustment in most banking rates is not influenced by the business cycle. These findings suggest that Islamic banking rates are less synchronized to the monetary policy rate, indicating that sharia-based banking barely supports counter-cyclical monetary policy.
Fiber Optics Improve Cement Performance and Drilling Cost in the Bakken
Authors: Jerrard Mark , Osborne Paul , Stark Price
Published: March 2022

The cement barrier represents the first line of defense to maintain well integrity on a multimillion-dollar asset, and an integral barrier for stage isolation for completion expenditures. The actual cement slurry design parameters are often based on historical precedent, trial and error, and simulation modeling but frequently have limited direct measured validation. What measurements have been completed, including wellbore static temperature measurements, are often known to be tens of degrees off from actual conditions. Cement placement effectiveness can be qualitatively evaluated via logging tools but is based on assumptions associated with the design and can be subjective based upon interpretation.

This paper will present a monitored cement slurry as, it cures in real-time, on two wells in the Williston Basin, H4 and H5.

The slurry designs were monitored via a fiber optic cable, pressure, and temperature gauges installed on the outside of casing. The pressure and temperature gauges were run concurrently with the fiber optic allowing further evaluation along the lateral during prejob circulation and the cementing operation.

The fiber optic cable and gauges were primarily deployed for completion evaluation and drainage mapping. Taking advantage of this equipment enabled monitoring of the heat of hydration of the cement slurry, and the annular pathways via gauges, from pump down through final curing along the entire lateral length.

The distributed temperature data provided visibility into the top of cement, curing temperatures, quality of circulation and curing behavior of the slurries. The observed Geothermal temperatures prior to cement placement were not consistent with previously reported temperatures via wireline or drill bit. The slurry design based on these temperatures responded to its actual downhole condition in a variety of surprising ways: (1) Slurry curing time was delayed beyond the heat of hydration predicted start time (2) heat of hydration of the slurry occurred at different depths along the lateral, possibly relieving hydrostatic pressure on the slurry column.

The wellbore itself, in one case, was observed to still contain obstructions in the annulus preventing a consistent slurry placement in both wells.

Adjustments to the design were necessary based on the data and implemented once observed. The implemented changes were cost neutral and significantly better results were observed in the fit for purpose, engineered cement slurry design.

The specific observations from this case study are not unique. In the last three years several cement monitoring programs have been conducted with similar results indicating a systemic issue in the industry regarding cement design.
Real-Time Estimation of Downhole Equivalent Circulating Density ECD Using Machine Learning and Applications
Authors: Robinson Tim , Gomes Dalila , Meor Hashim Meor M. Hakeem , Yusoff M. Hazwan , Arriffin M. Faris , Mohamad Azlan , Ezharuddin Tengku , Othman Eswadi
Published: March 2022

Despite many drilling technology improvements during recent years, hole cleaning remains a significant challenge. The variation of equivalent circulation density (ECD) is a symptom of borehole instability. Therefore, the ability to accurately estimate ECD is a key consideration for preventing hole cleaning problems that may lead to a stuck pipe, and well pressure management more generally.

In this work, we demonstrate a Machine Learning approach to estimating downhole ECD in real-time using a deep neural network. Surface measurements that are widely available from most rigs are used as the model inputs, hence less configuration information is required relative to hydraulic simulations for pressure loss. Mean Absolute Errors of ~0.3-0.4 ppg were achieved on 16 validation wells and 7 holdout wells (blind test); these wells were independent of those in the training data. Prediction errors often reflect offsets between reference and predicted values; however, even with these offsets, trends in ECD behavior can still be captured correctly. The model shows promise for real-time ECD monitoring purposes to complement existing numerical methods and downhole tools.

Beyond real-time estimation, other applications could include forecasting ECD a short time ahead to provide early indications of hole cleaning issues; case studies obtained from a real-time monitoring centre where this approach is used are presented as part of this work. The software tool was capable of detecting such symptoms in advance, giving the driller opportunity to take preventive actions to avoid a potential stuck pipe.
Behavior Anomalies Detection in Drilling Time Series Through Feature Extraction
Authors: Jeong Cheolkyun , Yu Yingwei , Patino Diego , Venkatakrishnan Sai , Mansour Darine
Published: March 2022

The industry has focused mainly on extracting key performance indicators (KPI) from its operational processes that aggregate data in different forms. The computation of average values has been one of the most important ways to measure process performance. However, averages or any other aggregate measures do not give a mechanism to identify how to improve a process. To detect abnormal activities with longer durations than normal (time anomalies), or not following the standard process (behavior anomalies), a drilling engineer has to manually review the drilling parameters individually. It is therefore essential to implement an automated mechanism to identify failures or anomalies within the process in real-time and provide feedback to field personnel in an efficient and easy-to-understand fashion to develop improvement plans.

To automatically identify time and behavior anomalies from the real-time surface data, the proposed workflow consists of three steps. First, the time sequence signal is split into drilling activities through data segmentation. Next, we extract features from the segmented activities and statistically convert the feature score into probability. Based on that, the system automatically judges whether it is an anomaly or not. The algorithm has successfully demonstrated its applicability in the field data with better interpretability.
Drilling Optimization in the U.S. New Mexico Permian Basin with a Compound Angle Motor in Monobore Wells
Authors: Borjas Francisco , Hollis Chris , Nabors John , Lopez Juan Ramon , Soberanes Juan Carlos , Feddema Chad
Published: March 2022

Drilling in the US Permian Basin is constantly evolving to optimize and reduce the total well construction cost. To be part of this fast-paced environment, operators and service companies should always engage in innovative thinking to find new ways to improve.

Several solutions are being tested every day in different disciplines of well construction that contribute to major breakthroughs in optimization. Examples of these are: novel technologies, different well designs, and artificial intelligence for automation, just to name a few. One known solution for cost savings in the well design category are monobore wells that have proven to save about 40% on average (Norwood et al. 2016).

Monobore projects utilize a single hole size to minimize different tool sizes for drilling and completions. While the reward is high, it should be carefully planned and analyzed to overcome any engineering challenges. For example, one major challenge an operator faced in Eddy County in conventional monobore wells is the geometry design for placement and optimum performance of an Electrical Submersible Pump (ESP). The well geometry required a specific design where within a curve section, a critical tangent section was required for optimum ESP operation. To accomplish this task several Bottom Hole Assemblies (BHA) with different bent housings are needed.

To solve this problem, a Compound Angle Motor was run in a conventional monobore application in the Permian Basin in New Mexico with great success. The concept uses a low degree internal tilt of the drive mandrel with a compound external bend (similar to conventional motors) but allowing the external bend to be much lower due to the existing pointed mandrel (Jones and Sugiura 2021). This translates in the ability to drill several sections with the same tool while having a more neutral BHA to improve trajectory control.

More than 19 wells utilizing the Compound Angle Motor have proven to provide substantial improvements in wellbore trajectory control, and asset utilization. In this Case Study we showcase these interesting results along with new challenges that emerge while pushing the limits.
Overcoming the Challenges for Cementing Salt Zones in Deepwater Top Hole Drilling in Brazilian Pre-Salt Wells: A Well Containment Barrier Approach
Authors: Moreira Rafael Peralta , Ribeiro Diego , Piedade Thiago
Published: March 2022

When a surface casing is set in front of salt zones, challenges such as hole enlargement and salt dissolution need to be addressed in the cementing design. This study compares the several possible solutions for drilling and cementing in deepwater top hole drilling with exposed salt formation, with the general objective to provide valuable insight on the relevance of cement integrity on well containment analysis in deepwater wells. Several studies reported in the literature have evaluated the different approaches that industry follows on drilling and cementing top hole sections when salt formations are present. In addition to a review on these practices, through a detailed analysis of field data from hundreds of wells in Santos basin pre-salt wells, we identify the main aspects of cement sheath quality and its ability to withstand well containment loads from cement slurry formulation to the drilling practices and geological conditions. From data in real scale, a new and robust design and its field results are presented. From the analytical study of several possibilities, it is shown that well geometry aspects - such as inclination, tortuosity, and hole enlargement – shall attend minimum requirements to obtain the desired cement sheath quality. These requirements were able to be established through extensive field data analysis and simulations for cementing in different conditions. When those requirements are not achieved, even the highest efforts on the sole cementing design does not mitigate the loss of well integrity. Another set of important conclusions are concerned the cementing slurry design and centralizer selection and placement: salt concentration in cement slurry, bond strength between salt formation and cement slurry stands as the key characteristic and the salt-based cement slurry with this property provided the best for specific field results. Since the industry is continuously discussing the best drilling and cementing practices on salt formations, this paper provides compiled results from a large field dataset on top hole drilling in deepwater wells. Furthermore, both theoretical and applied engineering considerations on the salt-based cement slurry design, its mechanical properties, and the placement environment (hole diameter, geology, and casing centralization) are addressed to bring on a discussion on general guidelines for cement sheath quality in well containment analysis.
Development of Online Drilling Fluid Property Logging System
Authors: Ge Yunhua , Mei Yunyi , Zhang Songjie , Zhang Yanlong , Liu Guanglai , Yang Hao , Wang Qi , He David , Zhang Josh
Published: March 2022

Continuously monitoring of drilling fluid properties and simulating of down hole hydraulics is critical and beneficial for safe and efficient drilling. However, the drilling fluids properties are generally taken once every regulated interval and the downhole wellbore conditions and drilling fluids performance are judged accordingly and sometimes experientially for lack of updated data. In this paper, we present a novel unit called On –line Drilling Fluids Properties Logging System (ODFPLS) for real-time measurement of drilling fluids property and software for downhole hydraulics modeling by integrating of these real-time measured data.

The ODFPLS unit consists of four testing modules, they are Density module, Rheology module, Funnel Viscosity module, and Ion Content module. During working, the fluid sample is sucked in and flowed first to the Density module, tested there and then flowed to other modules in above order and finally discharged into waste pits without any human intervention. The test data is stored in the database of well-site digital platform and shared to the Remote Operational Centers (ROCs) for drilling fluids performance diagnosis and downhole hydraulics modeling

The indoor and field pilot tests showed that the unit is capable of measuring fluid properties such as mud density, funnel viscosity, rheological behavioral parameters, calcium and chlorine concentration and so on properly and accurately while drilling compared with manual measurement by lab operators. The drilling fluids performance diagnosis and hydraulics modeling provides not only rheological mode identification but also the real time equivalent circulating density ECD and equivalent static density ESD at any point in the wellbore during drilling. It also delivers surge and swab pressure calculation as well as ECD data while tripping drill pipe or setting casing. The timely availability of the information enables the mud engineer and drilling engineer to aware the status and trends of the downhole conditions and improve efficiency in decision making.
Application of a Forced Vibration Modeling Approach to Better Quantify the Role of Downhole Vibrations and Excitation Tools
Authors: Nguyen Khac-Long , Mahjoub Mohamed , Dao Ngoc-Ha , Menand Stéphane
Published: March 2022

Drilling operations can induce several external excitations to the drillstring and bottom-hole assembly (BHA) due, namely, to the drillstring-wellbore contacts, bit-rock interactions, fluid flow, and mass imbalances. On the one hand, such undesirable excitations may lead to excessive vibrations and damage to the drill bit, BHA, or drill-pipes. On the other hand, some vibration tools are used to intentionally introduce a source of lateral vibrations in the drillstring to reduce the friction effects and enhance the rate of penetration. Whether these vibrations are undesirable or intentional, efficient models are necessary to predict them accurately to help optimize the drilling parameters and vibration tools placement in the drillstring.

The time-domain analysis can give a detailed portrayal of drillstring vibrations, but usually requires a lengthy computational time, especially for the simulation of long structures. This paper focuses on an alternative analysis using a forced vibration model based on a linearized frequency analysis. It consists of studying the magnitude of the displacement, velocity, acceleration, and internal efforts, when the drillstring is subject to an external harmonic excitation at a given frequency. This numerical model is based on the beam finite element method, where the wellbore-drillstring contact effects are considered using a Jacobian matrix approach.

The forced vibration model is applied to study the lateral vibrations produced either by mud motors or lateral vibration tools. The comparison between the results of frequency and time-domain analyses shows that the forced vibration model can describe the global behavior of drillstring vibrations with a fast computation. When varying the excitation frequency, critical values giving large vibrations could be identified and avoided by the driller thanks to a heat map representation of the vibration magnitude as a function of the position and excitation frequency.

The novelty of this work is in showing the capacities and limitations of the forced vibration analysis compared to time-domain analysis. The fast computation of the frequency analysis can provide efficient and accurate predictions and, therefore, could be employed to optimize the BHA design and drilling parameters, and therefore reduce the harmful vibrations and improve the performance of any drilling systems equipped with downhole excitation tools.
Construction of a Reference Well to Support the Qualification of Cement Evaluation Logging Tools and Data Processing
Authors: Beltrán-Jiménez Katherine , Merciu Ioan Alexandru , Gardner Dave , Govil Amit , Bose Sandip , Lomeland Stig , Hemmingsen Pål Viggo , Kuragina Olga , Godøy Rune , Mitelshtet Konstantin , Berg Eirik
Published: March 2022

Verification of annular well barriers is a critical process that can significantly affect the cost and complexity of plug and abandonment (P&A) operations, deep sidetracks, or any other drilled wells. Sonic, acoustic, and ultrasonic logging tools are nowadays used to evaluate the cement bond to the casing and infer information about the quality of the annular barrier seal. Nevertheless, as the comparison of the real annular condition and the log response can be uncertain or difficult to establish in a real well scenario, a well was drilled and completed with well-defined engineered defects introduced in the cement with the aim to establish a reference for assessing vertical and azimuthal sensitivity of the data delivered by logging tools. During the execution of this joint project between industry representatives and researchers, the first challenge was to select an appropriate material to simulate appropriate cement defects. Such material should have an acoustic response similar to water, be suitable for installation on the outside surface of a 9 5/8-in. casing, be robust enough to survive a trip downhole, and withstand the cement placement and curing process. After a screening process, four different synthetic rubber materials were selected as potential candidates worthy of further investigation. The characterization executed to select the material used included acoustic measurements and mechanical observations, as well as a detailed description of the well-designed and well construction procedure.

The reference well has a 12 ¼-in. section drilled to 214 mRKB and was completed with 9 5/8-in. casing. The completion design comprises the shoe, the float collar, and 17 casing joints fully centralized. Ten casing joints were run into the well with defects installed on the outside wall of the pipe simulating defects in the annular cement. The defects mimicked water channels of 10°, 20°, 30°, and 45° width. After landing the casing, a cementing operation was executed utilizing Class G cement of 1.90 SG. The first logging run confirmed all engineered defects had survived the trip downhole and that the goal of creating defects with well-defined geometries had been achieved.

The novel well facility was constructed with the aim of establishing a reference for the qualification of logging tools that can allow a direct comparison between log response and annular seal quality. This well provides the industry with the opportunity to compare different logging technologies to detect and evaluate cement defects and their performance to describe defects with specific lengths and sizes.
Accurate Prediction of Casing Collapse Resistance by 3D Finite Element Modeling
Authors: Lin Bisen , Coe David , Harris Richard , Klever Frans
Published: March 2022

Three-dimensional (3D) outside diameter (OD) and wall thickness mapping of a casing joint include synchronized OD laser scanning and wall UT (ultrasonic testing) measurement at a resolution of every 1-inch along the length and every 1 or 2 degrees around the circumference. This full-length mapping data can then be used to construct a 3D finite element analysis (FEA) model that captures the geometric attributes, including OD, wall thickness, OD ovality, and wall eccentricity of a casing joint. Together with the actual nonlinear material plasticity model and the measured residual stress, the 3D FEA model can accurately predict the casing collapse strength. Also, the Klever-Tamano ultimate limit-state (KT ULS) collapse equation per API TR 5C3 [1] together with a calibrated moving-average scheme was used to calculate the joint's collapse strength.

Results predicted by 3D FEA and KT ULS collapse models were then compared to the actual full-scale collapse test results. A 3D FEA model generally produces more accurate results than the KT collapse equation. In addition, both 3D FEA and KT collapse models predict slightly lower than actual collapse pressure, which therefore is on the conservative side.

The accurate prediction of casing collapse strength can be beneficial to the end user in sorting and ranking the casing joints by collapse resistance, and therefore provides valuable information that can be used in the end user's risk assessment with the consideration of the worst-case discharge scenario. Furthermore, the end user may potentially select the joints with the highest predicted collapse strength for the bottom portion of the casing string where the highest collapse resistance is desired.

In addition, the OD and wall mapping data together with the actual material tensile properties (yield strength, ultimate tensile strength, and strain hardening parameters) can be used in estimating the internal yield and ductile rupture pressures and other performance properties. This is outside the scope of this paper and can be pursued in future work. These predicted casing performance properties may then be used in sorting and ranking the joints based on a specific performance property of interest or combination of performance properties.
IADC Code Upgrade: Bit and BHA Forensics Using Rig-Based Photographic Documentation Practices
Authors: Watson William , Dupriest Fred , Witt-Doerring Ysabel , Pastusek Paul , Sugiura Junichi , Procter Ray , Daechsel Dustin , Abbas Raafat , Shackleton David
Published: March 2022

This paper establishes uniform recommended industry practices for bit and bottom hole assembly (BHA) photo documentation. In addition to standardizing photo documentation this reference document contains a discussion and example photos which may be used as training material to aid the rig site team in determining the cause of the damage observed in the photos.

Effective field photo documentation and training to identify the causes enables the team to modify parameters used in real time or make other immediate changes in the BHA or drilling system with a higher degree of confidence they will increase drill rate or extend bit and BHA life. The field documentation also provides the basis for more detailed post-drill assessment or extensive redesign if needed.

While other data should be analyzed to confirm the cause, the damage that's observed in the photo documentation is the most important in directing the actual redesign effort. For example, downhole accelerometer data may indicate the presence of BHA whirl but whether this damages the bit in a given situation is unpredictable. Whirl may not be the priority of redesign unless the photo documentation shows a pattern of damage that is known to be specifically due to BHA whirl.

These photo documentation practices were developed specifically to support real time drilling forensics. The guidelines were compiled from the practices of multiple operators, bit manufacturers, and service companies with significant experience in utilizing similar photo documentation practices to support real time decisions. The photo documentation is not complex and experience has shown that within a short period of training and daily discussions the collection of high-quality photos becomes a routine, sustainable practice.

The work described in this paper is part of a joint International Association of Drilling Contractors (IADC)/ Society of Petroleum Engineers (SPE) industry effort to revise the IADC dull grade manual.
Combining Downhole Axial and Surface Oscillation Tools, What Are the Consequences on Tool Face Control Performance?
Authors: Mahjoub Mohamed , Dao Ngoc-Ha , Nguyen Khac-Long , Menand Stéphane
Published: March 2022

When drilling in sliding mode, axial oscillation tools (AOT) and surface oscillation tools (SOT) are two possible solutions that are used in the industry to overcome the friction forces, especially in unconventional well trajectories with a long lateral section. The AOT is assembled in the drillstring and run in hole such that it is generally placed in the middle of the lateral section. It is actuated by the mud flow to produce high-frequency axial vibrations. As for the SOT, it is placed at surface and produces low-frequency torsional oscillations in the drillstring by alternating the rotation direction. For some challenging trajectories, the idea of combining both tools, where the SOT reduces the friction on the top part of the trajectory and the AOT deals with the bottom part, seems appealing. However, when coupling the two types of oscillations, one should be careful to the possible implications on tool face control performance.

In this paper, time-domain dynamics modeling is used to investigate the AOT and SOT behavior, whether they are employed separately or together. When simulated separately, the tools' influence zones can be identified, and their operating parameters can be tuned accordingly. When combining both tools, if their influence zones are overlapping, coupled axial and torsional oscillations occur and could have consequences on the tool face orientation (TFO). The observations obtained from simulations are confronted to data coming from a well drilled with both tools.

Numerical simulations show that the AOT helps the propagation of the torsional motion downhole, because it takes a part of the friction that opposes the torsional oscillations. If the SOT and AOT parameters are jointly well calibrated, then the steering from surface becomes faster, and the tool face control becomes more accurate. However, if the SOT's parameters are calibrated without regard to the AOT influence, then TFO variations could be obtained, indicating unstable tool face control leading to a tortuous well bore.

The use of time-domain modeling to jointly characterize the behavior of downhole axial and surface oscillation tools introduced in this work allows a better understanding of the coupling between the two tools. This work provides an opportunity to increase the extent of the lateral sections without impairing the wellbore quality.
IADC Code Upgrade: Data Collection and Workflow Required to Conduct Bit Forensics and Create Effective Changes in Practices or Design
Authors: Watson William , Dupriest Fred , Witt-Doerring Ysabel , Sugiura Junichi , Pastusek Paul , Daechsel Dustin , Abbas Raafat , Shackleton David
Published: March 2022

This paper introduces a forensic workflow that may be used to link drill bit and bottom hole assembly (BHA) damage to drilling dysfunction. This paper will also discuss the data that should be collected and how it should be processed to enable the operational practices and engineering design changes to address these issues.

There is a vast amount of data collected in all drilling operations that can be used to improve performance if utilized within an effective forensic workflow. Several drilling forensic case studies were developed and critically reviewed by subject matter experts from across the industry. From the causal analysis for each case study an assessment was performed on what information was (A) available, (B) required to diagnose the cause and (C) not available but would have been preferred. The way the team communicated and acted on the data was also documented.

By combining the learnings from these case studies, it was observed that a guided approach can improve data collection and lead to a more consistent, accurate, timely causal analysis with appropriate remedial actions. The process discussed within has been refined to support data collection for forensic analysis and provides a reference for field and office-based drilling professionals. These practical guidelines have been developed to offer a foundation for a drilling forensic data collection methodology as well as training for the industry - they have been created such that they can grow organically and, in the future, can be used for developing subsequent industry publications.

The work described in this paper is part of a joint International Association of Drilling Contactors (IADC) / Society of Petroleum Engineers (SPE) industry effort to revise the IADC dull grade manual.
Development of Automatic Recognition and Recording System for Rig Jobs
Authors: Ge Yunhua , zhang Yanlong , Ge Su , Mei Yunyi , Wang Wenzhi , Yong Fengwei , He David , Zhang Josh , Wang Zhenyu , Wang Yuxin
Published: March 2022

Keeping a record of drilling process automatically in real time is a requisite for KPI studies and getting support from ROCs experts. There are five categories of technical data describing a well's drilling process, which are rig jobs in time sequence, job operational parameters, unit lithology by depth, wellbore configuration by depth and job appraisal respectively. Among them, the data of rig jobs in time sequence covers whole process of well construction and is collected manually via Daily Drilling Reports or Shift forms with little data quality control and is easy to be filled by mistakes or omissions. The other four types of data are mainly collected via mud logger, MWD/LWD tools, wire-line logging tools, etc and mostly realized automatic recording with strict data quality controls. In order to solve the shortcomings of data collecting and recording of rig jobs in time sequence, an automatic recognition and recording system for rig jobs is developed.

Previously, the team had tried to identify 25 common rig jobs such as on-bottom drilling, tripping-in, tripping-out, circulating, reaming, etc by developing a judgment algorithm based on real-time operating parameters from mud logger and is proved to be inaccuracy and incompleteness due to insufficient data resolutions and limited data points especially when drill string is out of hole. This time, the team takes advantages of video data from on-site surveillance cameras and develops an automatic recognition and recording system for rig jobs by integration of AI video recognition algorithm with previous method. The AI video recognition is realized by applying U-Net, Attentioned, GAN, etc. and the AI model trained by a mass of labeled data. Finally, the system is deployed in sync with Wellsite Data Platform (WDP) and tested on line with real-time data from both cameras and mud logger.

The online tests showed that the system could recognize various rig jobs from spud-in to end of well with correctness rate of more than 97% and improved the correctness rate of previous method by more than 20%. In May to November of 2020, the system was first deployed in sync with WDP in a deep exploration well GQ-6. The video and mud logging data of its six drilled offset wells were loaded, replayed, and the rig jobs in time sequence of each well were recognized and recorded in the WDP database. With share of the accurate rig jobs data, the ROC experts could easily find out the causes of NPT and ILT and optimize drilling operations to realize the well GQ-6 the fastest well in the block The system also save much of manual work for data record of rig jobs.