bluuebunny/crossref_metadata_2025 huggingface dataset:
Faktor-Faktor Yang Mempengaruhi Pendapatan Usaha Wirausaha Baru Pada Sektor Ekonomi Kreatif Di Kota Banjarmasin
Authors: Prawitasari Trie , Yunani Ahmad
Published: March 2022

This study aims to (1) analyze the factors that influence the income of new entrepreneurs in the creative economy sector in Banjarmasin City (2) analyzing the dominant factors affecting the income of new entrepreneurs in the creative economy sector in Banjarmasin City. This type of research is a quantitative study using primary data obtained from questionnaires. Data was calculated by multiple linear regression analysis through the SPSS 26 program.The results of this study prove that the factors of working capital, education, age, working hours, and gender statistically jointly affect business income. This means anything of the size or level of working capital, education, age, working hours, and gender will greatly affect the income of new entrepreneurs in the creative economy sector in Banjarmasin City. In addition, this study proves that working capital is a dominant factor influencing the income of new entrepreneurs in the creative economy sector in Banjarmasin City. It can be seen that the results of the research have the most significant effect. This is caused by working capital is a factor that plays an important role in running a business.
Situasi Gamelan Solo Raya: Studi Kasus Gamelan Kyai Rejeki di Kabupaten Boyolali
Authors: Saputra Novyandi
Published: March 2022

IntisariSolo Raya merupakan daerah basis gamelan. Gamelan tersebar dan menjadi bagian yang tak terpisahkan dari kehidupan masyarakatnya. Salah satunya adalah keberadaan gamelan Kyai Rejeki atau gamelan Gombang yang bergaya semarangan di desa Gombang kecamatan Sawit kabupaten Boyolali. Tujuan penelitian ini adalah mengidentifikasi frekuensi, jangkah nada-nada dan satu gembyangan dari gamelan Kyai Rejeki (Gamelan Gombang). Pada penelitian ini, peneliti menggunakan metode kualitatif dan metode kuantitaif sebagai metode bantu dalam peghitungan sistem nada. Observasi, wawancara dan data ukur menjadi data fundamental yang digunakan selama penelitian. Gamelan kyai Rejeki atau yang lebih akrab disebut gamelan Gombang merupakan salah satu gamelan terkemuka dan yang menjadi patron atau babonan gamelan-gamelan yang ada di sekitar kabupaten Boyolali sampai daerah Klaten dengan gaya semarangan. Gamelan kyai rejeki merupakan gamelan gaya semarangan dengan kebanyakan permainanannya berada pada wilayah nada tinggi termasuk dalam hal garapan. Penelitian ini berhasil mengidetifikasi sistem nada, jarak antar nada dan gembyangan. Peneliti juga menemukan adanya kebiasaan permainan dan garapan gamelan ini berada pada wilayah nada-nada yang tinggi.Kata kunci: gamelan kyai rejeki, gombang, sistem laras, slendro, boyolali       AbstractSolo Raya is a gamelan base area.  Gamelan spread and became an inseparable part of people's lives.  One of them is the existence of the Kyai Rejeki gamelan or Gombang gamelan with semarangan style in Gombang village, Sawit sub-district, Boyolali district. The purpose of this study was to identify the frequency, range of notes and one gembyangan of the Kyai Rejeki Gamelan (Gombang Gamelan). In this study, researchers used qualitative methods and quantitative methods as auxiliary methods in calculating the tone system.  Observations, interviews and measurement data became the fundamental data used during the research.  Kyai Rejeki Gamelan or more familiarly called Gombang Gamelan is one of the leading gamelan and the patron or babonan of gamelan around Boyolali district to Klaten area with semarangan style.  Kyai Rejeki gamelan is a Semarangan style gamelan with most of its playing in the high-pitched region, including in terms of production.  This study succeeded in identifying the tone system, the distance between notes and its gembyangan.  The researcher also found that the habit of producing and playing this gamelan was in the high-pitched region.Keywords: kyai rejeki gamelan, gombang, tuning system, slendro, boyolali
EQUITY OF TRANSIT NEED IN BAGHDAD CITY
Authors: ASMAEL Noor M. , WAHEED Mohanned Q.
Published: March 2022

Public transportation plays a significant role in urban areas, transporting a large percentage of people. There is no existing study dealing with the balance between transportation demand and supply in Baghdad city; thus, there is a need to assess service equity before implementing any major services. The aim of the present research is to study the equity of transit need. The methodology uses geographic information systems (GISs) and spatial multi-criteria analysis to determine equity. Nine criteria were used in this study (land use, population density, commercial activities, medical locations, bus stops walkability, educational activities, bus terminal, and income) to determine a transit need map. Expert opinion surveys are conducted to determine pairwise comparisons between these criteria to estimate the weight of each criterion. Spatial analysis in ArcGIS 10.8 is utilized to apply methodology. The transit need map is obtained, and the need for transit service is represented by a value for each cell. In addition, the map output is important to public transit planning, as it maximizes the optimal transit route selection depending on the transit need. The output of this study (a transit need map) represents a powerful tool for the decision-makers to prioritize transportation programs and ranking alternatives. Gap analysis is used to measure equity between various zones. The results show that the transit supply provides higher service coverages in the Central Business District (CBD) and decreases as the distance to CBD increases.
VEHICLE RELOCATION EFFICIENCY – A CASE STUDY OF THE PARKING COMPANY IN THE CITY OF ZAGREB
Authors: ŠIMUNOVIĆ Ljupko , PROTEGA Veselko , ĆOSIĆ Mario , BANDOV Davor
Published: March 2022

There is a need for vehicle relocation, whether for delivering new vehicles to their selling destinations, pulling inoperative or damaged vehicles out of traffiic, or removing illegally parked vehicles from the street. The relocation of illegally parked vehicles in the City of Zagreb is done by constantly monitoring parked vehicles or through citizen telephone alerts. The paper analyses the vehicle relocation service of the Zagrebparking company, which, in addition to overseeing car park management in public car parks and garages, is in charge of removing illegally parked vehicles. Due to the cyclic nature of its operations, a high share of empty rides, high vehicle investment costs, small quantities of cargo transported, high fuel prices, and high fuel consumption in the urban environment, Zagrebparking’s Vehicle Relocation Department operates with unnecessarily high costs. In this paper, vehicle relocation efficiency is analysed by presenting indicators of vehicle utilisation as part of a systematic evaluation of the company. Improvements to the current service are also provided.
The Solid Tumor Microenvironment - Breaking The Barrier For T Cells
Authors: Simsek Hasan , Klotzsch Enrico
Published: March 2022

The tumor microenvironment plays a pivotal role in the behavior and development of solid tumors as well as shaping the immune response against them. As the tumor cells proliferate, the space they occupy and their physical interactions with the surrounding tissue increases. The growing tumor tissue becomes a complex dynamic structure, containing connective tissue, vascular structures, and extracellular matrix that facilitates stimulation, oxygenation, and nutrition, necessary for its fast growth. Mechanical cues such as stiffness, solid stress, interstitial fluid pressure, matrix density, and microarchitecture influence cellular functions and ultimately tumor progression and metastasis. In this fight, our body is equipped with T cells as its spearhead against tumors. However, the altered biochemical and mechanical environment of the tumor niche affects T cell efficacy and leads to their exhaustion. Understanding the mechanobiological properties of the tumor microenvironment and their effects on T cells is key for developing novel adoptive tumor immunotherapies.
Using Potential Dependent Special Relativity, Gauss’s Law, and Schrodinger Equation to Find Vacuum Quantized Energy and Elementary Particles Mass
Authors: Saad Zoalnoon Ahmed Abeid Allah , Yagoubb Mubarak Dirar Abd-Alla , Shirgawi Mohammed Mohamed Yahia , Yousef Mashair Ahmed Mohammed
Published: March 2022

Potential dependent special relativity and Gauss's law for the electric field have been used for gravity by assuming vacuum energy to be generated when the energy is a minimum useful expression for vacuum energy has been found. This expression shows that elementary particles are generated by gravity vacuum filling their hollow balls; using Schrödinger equation for spherically symmetric particles vacuum energy is quantized. Treating mass as vibrating spheres thus solving Schrödinger, coordinate harmonic oscillator energy relation has been found.
Classical-Relativistic Variability of Inertia of Photon Displacement Mass in the Matter and the Specific Vacuum Temperature
Authors: Cardoso Daniel Souza , Bordin José Rafael
Published: March 2022

The effects of photon inertia on the determination of its trajectory were verified and the representation of a displacement mass characterized by the flow of the number of wavefronts and the decomposition of photon inertia into parts associated with translation and rotation motions was considered. It was found that with the relativistic increase of the photon's resistance to change its directional properties, it inhibits the relativistic trajectory of the second torque, of Minkowski, in an angular range of incidence. After synchronizations, in the OAM inversions, there are reductions of the inertia associated to the translational part that assumes classical predominance, where the relativistic trajectory is allowed while the photon offers less resistance to changes in its directional properties. The classical-relativistic variability of the photon inertia characterizes the classical or relativistic profile of the energy distribution in forms of motion, where adjustments of the rotational and translational parts can be performed as a function of the refractive index rate, temperature and angle of incidence. It was found that with increasing temperature of the refringent medium, the synchronizations displacement in the sense of the normal incidence. A specific vacuum temperature for the refringent medium was characterized, where the photon exhibits a classical-relativistic synchronization under all angles of incidence, characteristic of its immaterial state in vacuum.
Recommendations from the ICM-VTE: Hip & Knee
Authors:   The ICM-VTE Hip & Knee Delegates
Published: March 2022

Update

This article was updated on June 17, 2022, because of a previous error. In the note on page 231, the name “Armin Arish” now reads “Armin Arshi.”

An erratum has been published: J Bone Joint Surg Am. 2022 Aug 3;104(15):e70.
Improved Radiation Exposure Monitoring of Orthopaedic Residents After Institution of a Personalized Lead Protocol
Authors: Massey Patrick A. , Myers Mitchell E. , Guedry Ryan D. , Lowery Michael T. , Perry Kevin J. , Barton R. Shane
Published: March 2022

Background:

Radiation exposure of orthopaedic residents should be accurately monitored to monitor and mitigate risk. The purpose of this study was to determine whether a personalized lead protocol (PLP) with a radiation monitoring officer would improve radiation exposure monitoring of orthopaedic surgery residents.

Materials and Methods:

This was a retrospective case-control study of 15 orthopaedic surgery residents monitored for radiation exposure during a 2-year period (March 2017 until February 2019). During the first 12-month period (phase 1), residents were given monthly radiation dosimeter badges and instructed to attach them daily to the communal lead aprons hanging outside the operating rooms. During the second 12-month period (phase 2), a PLP (PLP group) was instituted in which residents were given lead aprons embroidered with their individual names. A radiation safety officer was appointed who placed the badges monthly on all lead aprons and collected them at the end of the month, whereas faculty ensured residents wore their personalized lead apron. Data collected included fluoroscopy use time and radiation dosimeter readings during all orthopaedic surgeries in the study period.

Results:

There were 1,252 orthopaedic surgeries using fluoroscopy during phase 1 in the control group and 1,269 during phase 2 in the PLP group. The total monthly fluoroscopy exposure time for all cases averaged 190 minutes during phase 1 and 169 minutes during phase 2, with no significant difference between the groups (p < 0.45). During phase 1, 73.1% of the dosimeters reported radiation exposure, whereas during phase 2, 88.7% of the dosimeters reported radiation exposure (p < 0.001). During phase 1, the average monthly resident dosimeter exposure reading was 7.26 millirems (mrem) ± 37.07, vs. 19.00 mrem ± 51.16 during phase 2, which was significantly higher (p < 0.036).

Conclusions:

Institution of a PLP increased the compliance and exposure readings of radiation dosimeter badges for orthopaedic surgery residents, whereas the actual monthly fluoroscopy time did not change. Teaching hospitals should consider implementing a PLP to more accurately monitor exposure.

Level of Evidence:

3.
Production characteristics of Porphyridium purpureum (Bory) Drew et Ross semi-continuous culture at low irradiance
Authors: Borovkov A. B. , Gudvilovich I. N. , Novikova T. M. , Klimova E. V.
Published: March 2022

The red microalga Porphyridium purpureum (Bory de Saint-Vincent, 1797) Drew et Ross, 1965 is of great interest to researchers as a source of various biologically valuable substances, with their content in cells being determined by cultivation conditions. Phycobiliproteins concentration in P. purpureum cells depends directly on nitrogen concentration in the culture medium and cell irradiance. Semi-continuous cultivation allows maintaining these parameters at a level given. The aim of the work was to study P. purpureum culture growth and B-phycoerythrin (B-PE) accumulation and production at low irradiance, with minimal rates of pigment photodestruction. P. purpureum semi-continuous (quasi-continuous) cultivation was carried out at a specific flow rate of 0.1 and 0.2 day−1 and mean surface irradiance of 5 and 25 W·m−2. P. purpureum culture productivity increased by 1.6–17 times both with a rise in surface irradiance 5 to 25 W·m−2 and an increase in the medium specific flow rate 0.1 to 0.2 day−1. Maximum productivity values for the experimental conditions (0.21 g·L−1·day−1) were recorded at 25 W·m−2 and 20 % medium specific flow rate, but those were 1.5–2 times lower than the precalculated ones. In P. purpureum cells, protein and B-PE concentrations decreased both with an increase in surface irradiance (by 15–20 %) and with a rise in a specific flow rate (by 1.5 times) for all the variants. The shifts in protein and B-PE concentration in P. purpureum culture had a unidirectional character as well; those mainly corresponded to the shift in the culture density. P. purpureum B-PE productivity increased by 1.5–1.9 times with a rise in surface irradiance 5 to 25 W·m−2. Maximum B-PE productivity (13 mg·L−1·day−1) was recorded for the variants of the experiment with a surface irradiance of 25 W·m−2 (0.1 and 0.2 day−1). An increase in specific irradiance of P. purpureum cells 7 to 26 W·g−1 resulted in a rise in biomass productivity by 2.6 times; in B-PE productivity, by 1.8 times; and in protein productivity, by 1.7 times. In the experiment, irradiance was the factor determining the production characteristics of P. purpureum culture, and it was confirmed by the data obtained.
The Foundations of Pakistan’s Strategic Culture: Fears of an Irredentist India, Muslim Identity, Martial Race, and Political Realism
Authors: Briskey Mark
Published: March 2022

This article examines the early foundations of the strategic culture of the Pakistan Army. By exploring the impact of the partition of British India in 1947 and the First Kashmir War of 1947–48, the article identifies the pivotal factors in the development of strategic culture of Pakistan. In also examining Pakistani fears of a “vengeful” Hindu India and a persistence in the belief of discredited martial race theories as well as the idea of a Muslim military exceptionalism, the article concludes that the foundation of this culture remains evident while it is also malleable to contemporaneous events.
Gas Well Deliquification Strategy in Sultanate of Oman
Authors: Veeken Cornelis , Al-Rashdi Ahmed , Al-Hashami Ahmed
Published: March 2022

PDO is operating some 600 gas wells in the Sultanate of Oman and almost all these gas wells will experience liquid loading during their production life. Surface depletion compression and gas well deliquification are essential to sustain stable production and to maximize ultimate gas recovery. This paper provides an overview of the deliquification measures that are assessed, adapted and implemented in PDO, and describes how to select the best suitable combination of deliquification measures based on well specific reservoir, inflow and outflow parameters.
Successful Polymer Flood Pilot Application in Lower Permeability Heterogeneous Sandstone Reservoir in the South of the Sultanate of Oman
Authors: Al-Sulaimani Hanaa , Al-Rawahi Zainab , Velazco Quesada Conny , Anand Adi , Hemink Gijs , Frumau Mervin , Al-Hussaini Azza , Syed Muhammad , Al-Zadjali Ruqaya , Mahajan Sandeep , Al-Yahyai Ahmed , Al-Mahrooqi Majid , Ajmi Jasim
Published: March 2022

This paper summarizes the performance of a polymer flood pilot conducted in an unconsolidated sandstone reservoir in the South of the Sultanate of Oman with the objective of extending the envelope of polymer flood applications to lower permeability (average 100mD) and highly heterogeneous reservoirs. The water flood baseline phase performance was presented previously in paper SPE-188408 where the connectivity of the patterns together with injectivity were established prior to polymer injection.

The main objectives of the pilot were to test ability to sustain injectivity of polymer into this particular reservoir, achieve sufficient water-cut reversal (10% or more), monitor polymer efficiency and evaluate operational impact on facilities due to sand production which was expected to increase with polymer flood.

Several lab tests along with a previous polymer injectivity trial data were fed into the selection of the appropriate polymer and injection design for this reservoir type. The pilot pattern layout consisted of an inverted five spot with injector-producer spacing of 75m. The injector was equipped with fiber optics for data acquisition and real time surveillance. Polymer injection commenced in December 2017 using relatively low molecular weight HPAM3430. The plan was to inject polymer for a year and evaluate the performance for a potential field scale development.

The fiber optics data acquisition has demonstrated clearly the injection conformance improvement during the switch from water injection to polymer. In addition, around 10% of incremental oil recovery was obtained with an average water cut reversal of 12% across the pattern where the total pattern recovery was over 30% (including the waterflood). In terms of sand production, no noticeable impact was found on the facilities from sand production due to the polymer. The pilot performance exceeded the pilot success criteria that were set prior to commencing the polymer injection in terms of water-cut reversal and incremental recovery over the waterflood and fall in line with the modeled high-end scenario.
Condensate Stabilizer Flooding Diagnosis
Authors: Al Sabri Abdullah , Dua Vipin , Abeebur Rahman Wasik , Idris Mufleh , Hameed Muddassir , Kindi Abdullah
Published: March 2022

Condensate stabilizers at PDO Saih Rawl Central Processing Plant experienced severe pre-mature flooding causing process upsets and Operational difficulties. Conventional steady state simulations and tray hydraulics could not suggest actual causes. The purpose of the proposed paper is to present the methods followed in analyzing the flooding issue and identified solutions.

Initially, the flooding issue was analyzed by carrying out steady state process simulation with latest feed composition and tray adequacy checks in consultation with the tray supplier. The study concluded the existing hardware is adequate, jet flooding limit and down comer flooding levels well within acceptable limits. The study recommended only few adjustments in Operating conditions to resolve the issue. As part of verification, alternate tray suppliers were also approached to carry out tray hydraulic checks and found no concerns.

Subsequently, the column was subjected to gamma ray scan during normal operation and a scanning was repeated after simulating a flooding inside the column. Coupled with gamma ray scanning results, a tray by tray by simulation was carried out to ascertain the flooding the phenomena.

Gamma ray scan revealed the condition of the column internals, liquid heights and froth level during normal operation as well as during simulated upset conditions. Even though the trays were in good conditions, bottom few trays showed higher liquid height during normal operation itself. Along with the results from Gamma ray scanning, process simulation results and investigation of Operating conditions revealed the possible reasons for the flooding issue. The study predicted a temperature dip in few trays and further rise somewhere near the column top, which is unusual for a distillation column. This is the resultant of different feed ratios from the original design and one of the feed to the column is estimated to be below 5 °C, which is too cold compared to column profile. Based on the results, options were developed to alleviate the flooding issue without compromising the production capabilities of the column profile.

The nature of flooding experienced inside the column handling different feeds and large variation in temperatures is unique with the condensate stabilizers. Conventional full column steady state simulation and tray sizing were not adequate for investigating problem. It needed, gamma ray scanning while the column is in normal operation and during simulated flooding condition.
Brownfield Waterflood Management - Strategic Implementation of Field Trial Learning, South Oman
Authors: Abri Yaqoob , Choudhury Suryyendu , Harthi Mohamood , Anbari Ali , Lawati Ali , Ghatrifi Suhaib , Sabahi Atiya , Mahrooqi Iman , Marpaung Billman , Busaidi Hamood , Harthy Khalfan
Published: March 2022

Waterflood response in a brownfield with complex reservoir dynamics have significantly delayed the expected water injection response in Field ‘A’. The field is one of the highest oil producers in Oman South, spead over ~37 Km2, with more than 400 active wells, contributing > 90,000 BoE/d over the last 3 decades. The field is producing under strong bottom aquifer water drive and improved oil recovery waterflood. Current field development is focused in drilling horizontal in-fill wells and maximize recovery through well reservoir and facility management (WRFM). Production is from a combination of Mahwis aeolian and Al Khlata glacial reservoir formations. Sub-surface challenges are to arrest pressure decline, enhance sweep efficiency, ramp-up water injection (target > 440,000 BoE/d), and source additional water and manage complex operations. The produced water from oil producing wells post treatment gets re-injected into the aquifer ~100m below oil water contact (‘Deep Injection’) with 38 vertical injectors. This ‘Deep Injection’ albeit have prolonged water breakthrough has yet not delivered the optimum oil drive efficiency. One of the key subsurface challenge is the unfavorable mobility contrast between the oil and water causing early water breakthrough. Field wide variable mobility contrast, presence of intra reservoir baffles and enlarged size of the aquifer compared the legacy model assumptions triggered a transformation of the improved recovery strategy of the field – both short term and longer term. More effective injection strategy through ‘Field Trials’ have now been deployed (viz. ‘Water Re-Distribution’, ‘Make-up Water Diversion’ and ‘Shallow Injection’) over the last two years. Initial response from these trials shows encouraging results in terms of pressure support and sweep efficiency. Learning from the trails are incorporated in the future development and asset management strategy.

This paper highlights the ‘Field Trials’ – practical approaches implemented to manage and optimize the field performamance. In a cost competitive low oil price time the team focused in enhancing efficient and impactful trials which yields short-term production gains keeping in mind the longer term persepective.
Surfactant-Polymer Compatibility in Bulk and Static Conditions vs. Confined and Under Flow Conditions
Authors: Marliere Claire , Miralles Vincent , Morgand Claire , Rome Virginie , Le Bris Aymerick , Guilloteau Chloé , Courtaud Tiphaine , Rousseau David
Published: March 2022

The objective of surfactant-polymer (SP) formulation design is to simultaneously achieve ultra-low interfacial tension and good mobility ratio. However, in some cases, the presence of both polymer and surfactant can cause compatibility issues leading to a cloudy or even demixing solution. Until now, those observations were made in bulk conditions but the assessment of this behavior has not been studied in confined and under flow conditions.

Three SP compatibility cases were selected using the same SP formulation and playing on the brine salinity (low, medium and high). Bulk and kinetic studies based on solubility, viscosity and cryo-TEM were performed prior to monophasic injections carried out in a transparent micromodel representing a 2D rock porous medium and in a coreflood rig with a 3D outcrop rock. The observation in micromodel was performed using an optical microscope under polarized light to visualize the physical structure of the SP formulations. The pressure drop along the core was monitored during coreflood experiments to measure the mobility reduction entailed by the injected solution.

In bulk conditions it is shown that increasing the solution salinity leads, after a few to several days depending on the solution's volume, to a degradation of the SP compatibility or even demixing. This behavior can be attributed to depletion effects. In this case, depletion is due to the formation of surfactant vesicles (hundreds of namometers in size) that tend to aggregate in the presence of polymer molecules.

As expected, injection of the compatible SP solution (at low salinity) in the 2D porous medium micromodel and in the outcrop rock led to an easy in-depth transport, namely mobility reduction compatible with the viscosity of the solution. More interestingly, the same formulation at higher salinity exhibited a deposit of SP aggregates having a crystalline structure when injected in the micromodel. However, this formulation at high salinity did not show any issue in terms of mobility reduction when injected in the outcrop rock as the mobility reduction stabilized rapidly at a value close to the relative viscosity of the solution. These results highlight that the presence of a demixing phase does not always induce propagation issues in cores and that some cloudy SP solutions could be injected without causing any pressure increase.

The objective of this study was to correlate the bulk behavior of SP formulations showing respectively good and poor compatibilities with their performance in confined and under flow conditions. It has been proved that a poor compatibility in bulk does not always induce transport issues when the solution is injected in porous medium, despite the deposit of structured aggregates in some pores.
Well Revival in an Offshore Marginal Field Using Through Tubing Straddle Gas Lift Technology - A Case Study
Authors: Vijay Rachit , Khanna Manu , Sarma PJ
Published: March 2022

LG is a marginal offshore field lying in the west coast of India. Well A and B in field LG were completed using 4 ½ - in and 3 ½ - in single-string multizone completion intersecting gas and oil-bearing zones. During the initial phase of its production, the wells only produced gas, until the oil-bearing sands were perforated, and the wells produced commingled gas and oil. These wells had been flowing naturally on self-drive and recently ceased to flow after showing gradual decline in their production. The diagnosis suggested a failure of Vertical Lift Performance (VLP) indicating a need to change the production technique and possibly a need for artificial lift in the wells to bring them online.

The paper discusses an innovative and cost-effective approach involving the implementation of through-tubing mechanical straddle pack-off with gas lift assistance to bring the wells back to production and increasing the overall recovery from the field.

A detailed analysis of the various techniques for bringing the well online was evaluated keeping in mind the associated cost and time for each method. The considerations lead to the plan of introducing gas lift as an artificial lift method for these wells. Wells A and B were not equipped with any gas lift mandrel for introducing artificial gas lift. Workover for these wells would result in higher cost, time & risk factors for the wells. The economic viability of such a workover was not justifiable given the incremental production anticipated.

After performing a detailed technical and economic analysis, the decision was made to implement a through-tubing gas lift technique using a straddle packer conveyed on slickline across the circulation Sliding Sleeve Door (SSD). The straddle pack-off was to be introduced in the existing 4 ½ - in and 3 ½ - in production tubing with internally mounted gas lift mandrels/orifice valves. Detailed modelling was performed to determine the correct orifice size for different lift parameters.

The operations in candidate wells A and B were successfully conducted and the surface setup for the gas lift was installed. The mechanical pack-off was set at the desired depths without any issue, and the gas was injected through the annulus leading to instantaneous production from the well. The total operations period was minimal as compared to the workover operations, far safer and more cost-effective for the production enhancement achieved.

This paper describes the job design, technique implemented, and challenges overcome during the successful activation of a theoretically dead well to 1000 BOPD production, establishing the viability of through-tubing gas lifting. Learnings from the paper will help professionals plan for such well interventions involving the use of mechanical straddle pack off for gas lift operations.
Challenges in O&G Material Selection: Experiences and Case Histories
Authors: Cavassi Paolo , Chiodini Vittorio , Franci Stefano , Torri Lucia
Published: March 2022

The paper gives an overview of recent issues in Oil & Gas material selection, as resistance to high levels of H2S, and quality control during production of Carbon Steel and Clad pipes for pipelines, with reference to real cases.

Each topic under discussion is first described showing the relevant issues in terms of materials available on the market, failure mechanisms and possible consequences during the service life. Then the challenges are analyzed by mean of a brief review based on the main and most recent corrosion related conferences. Then, making reference to case histories taken from recent offshore development projects, the Company experience is described, highlighting the technical solutions taken and the main results obtained.

The first challenge discussed is the corrosion resistance of pipeline materials for transportation of fluids with high levels of H2S. The carbon steel pipes used for large diameters pipes are commonly manufactured with the TMCP, Thermo-Mechanical Controlled Process method. In severe sour service applications they showed to be susceptible to SSC, Sulfide Stress Cracking, due to hard zones that can originate at surface during pipe manufacturing. New non-destructive tests have been developed for the detection of hard zones during pipe production. Besides, SSC tests have been performed on API 5L X52 and X60 pipes samples at H2S partial pressure higher than 10 bar, which gave surprising results.

Clad and lined pipes represent alternative materials to TMCP carbon steel, but they are expensive and only few manufacturers are available, with consequence in terms of long delivery time. Furthermore, these materials are not immune to technical problems, as the precipitation of intermetallic phases in the nickel alloy layer during heat treatment.

The paper describes the Company experience made in offshore projects where both TMCP carbon steel and clad pipes have been used for pipelines and buckle arrestors.

The corrosion and cracking problems described in the paper are relatively new, as well as the technical solutions adopted. New field experience represents additive information to existing literature.
Mukhaizna Steam Flood Project: Thermal Surveillance Practices and Log Response
Authors: AL-Qassabi Sultan , Al Rahbi Mohammed , Al Habsi Ali , Al Shaibi Rashid
Published: March 2022

Mukhaizna is a heavy oil field located in southern Oman. The heavy oil (700 to 3900 cP at reservoir conditions) was found at a true vertical depth of 2000 to 2460 ft, which is considered rather deep for a steam flood. Initial reservoir pressure was 1,300 psi, and the initial temperature was 122°F. The field has been developed with horizontal producers, vertical steam injectors, and vertical infill producers in patterns of about 67 acres in size. To date, 3000+ wells have been drilled in Mukhaizna field, and a huge amount of Petrophysical data has been acquired.

Petrophysical surveillance work provides monitoring of time lapse thermal efficiency sweeping, perforation picking strategies of hot, swept and cold zones, as well understanding open hole log response in thermal hot wells. Using this information, we were able to target the correct zones to improve the thermal sweep and increase oil production.

The first part of this paper will describe the open-hole log response in thermal wells and how perforation intervals are picked based on this log response. These perf picks were later corroborated with well production data to ensure alignment with well production performance.

The second part of this paper will present a field-specific correlation of steam quality measured at the separator with spinner surveys at wellhead injectors, aiming to estimate steam quality directly from a spinner survey without having to run a steam quality separator, which is time-consuming and involves extensive effort.
Implementing ASP Without Water Softening in Reservoirs With Low Concentrations of Divalent Ions
Authors: Farsi Samya , Bouwmeester Ron , Brewer Mark , Southwick Jeff , Mahruqi Dawood , Karpan Volodimir , van Batenburg Diederik , Carpenter Ian , Wilson Sam
Published: March 2022

Alkaline Surfactant Polymer (ASP) flooding has proven to be an effective method to recover residual oil after waterflood. Yet, there are several complications that limit a wide implementation of ASP. The source water needs to be softened to avoid injectivity issues due to scale formation when alkali is mixed with divalent cations. Even when softened water is used as base water, scaling can still be an issue in producing wells due to mixing of waters with different compositions in-situ. Scale control by means of scale inhibitor squeezes on the production side or scale inhibitor on the injection side have been reported to be successful for some cases.

Carbonate scaling issues are most severe when sodium carbonate is used as alkali. Even if alkalis other than carbonate are used, carbonate scale remains an issue as bicarbonate that is present in almost any formation water, will convert to carbonate at high pH and will subsequently precipitate with the divalent ions present.

Ethanolamine has been proposed as an effective alkali in ASP application with high TAN oils for reservoirs that contain relatively low concentrations of divalent ions in their produced water that is reinjected. ASP implementation could significantly be simplified if softening of the produced water could be avoided.

Results of a study that involved determination of scaling tendencies, compatibility testing, tube blocking tests, and core floods with and without the addition of scale inhibitor will be presented together with implications for field implementation. A potential additional advantage of adding scale inhibitor on the injection side is that the scale inhibitor travels with the components to be inhibited. This might eliminate the need for scale control measures at the production side.
In-Situ Stresses and Geomechanical Properties Characterization Using Robust Optimization Approach, Tested in a Tight Gas field, Sultanate of Oman
Authors: Saidi Hamdan , A-Aamri Mohammed , Al - Senani Ahmed , AL-Aani Khalid
Published: March 2022

Knowledge of in-situ stresses and geomechanical properties is important for wellbore stability and hydraulic fracture optimization applications. Both mechanical rock properties (e.g., Young's modulus and Poisson's ratio) and the stresses represent the initial step in constructing a geomechanical model that will eventually require static calibration from the lab or field tests. Nonetheless, a wellbore deformation-based inverse analysis solution has become an alternative method that characterizes in-situ stress in particular. In this paper, a genetic algorithm and probabilistic analysis methods are proposed and integrated into a well-drilled known analytical method to characterize both stresses and geomechanical properties.

Systematic steps have been applied to this analysis. First, borehole geometry (i.e., multi-arm caliper), mud weight, and vertical pressure (from the density log) are well-defined inputs for deformation-stress relationships. Unknown parameters have also been determined and include horizontal stress, Poisson's ratio, and Young's modulus. Subsequently, the minimum and maximum expected values for each unknown parameter have been defined. Thousands of combinations have been created by the analytical equation (fitness function). In addition, the semi-genetic algorithm concept was used as an optimization method to find the best solution from a wide range of inputs for a given fitness function. The first hundred strongest fitness combinations were then chosen for the next level, which had a noticeably higher frequency number using the statistical analysis technique. The approach was checked with a real field example, the results indicated the measured values of geomechanical properties, and horizontal stress were reasonably consistent with the actual field data and previous studies in the field. In particular, the proposed approach allows for a realistic estimate of the most difficult stress (i.e., Max horizontal stress), which was ~45 % higher than minimum horizontal stress.

The proposed technique was developed to reduce in-situ pressure uncertainties and geomechanical properties for the studied area. Results from this paper presented a simple and practical alternative method for the determination of geomechanical parameters using a simple logging tool (e.g., a caliper) that theoretically provides a robustness guide for wellbore stability and hydraulic fracture models for tight gas fields.
Evergreen Forecast & Predictive LTRO Using Machine Learning – Case Study from PDO South
Authors: Mahaldar Sahil , Singh Jasbindra , Riyami Abdullah , Mahrooqi Nasser , Abri Mohammed , Mandhari Sulaiman , Hikmani Salwa , Al Humaid Maitham , Sinani Yousuf , Mahruqi Issa , Al Azri Nasser , Mohajeri Sina
Published: March 2022

Digital transformation (Dx) is increasingly becoming a key enabler in oil and gas industry to reduce costs, make faster and better decisions and increase productivity. The difference between leading the next innovation wave or being left behind may depend on how proficiently we embrace digital enablers, and how quickly we can test, prototype and scale these digital solutions to create value for the business.

Digital technologies are not new to Petroleum Development Oman (PDO). In fact, the company has a track record of testing and adopting a wide range of new technology and integrated organisational capabilities to improve its business performance. Significant investments have been made into instrumenting its fields, including the IT infrastructure, Real-Time Operations, Exception Based Surveillance, Collaborative Work Environment (CWE), Smart Fields, NIBRAS, data management, analytics trials, to name a few. Yet consensus that Dx has significant further upside across PDO, led to the initiation of an asset-led pilot to digitally transform an existing PDO South Field – "S". The focus of the pilot was to identify new Dx opportunities while leveraging on existing PDO investments into digitalization, leading to quantified improvement in business performance of field –S. The project workscope was based on the outcome of an Opportunity Framing Event (OFE), in which a total of 27 opportunities were identified and ranked in terms of business value vs. feasibility or cost of implementation (Figure 1). Technical Subject Matter Experts (SMEs), asset field - surface, sub-surface, data management teams and other relevant support functions participated in the OFE so that business improvement synergies could be identified across the multiple disciplines in an integrated fashion.

Following an agile approach, 5 Valuestreams (VS) were selected for Minimum Viable Product (MVP) implementation, in phase 1 of the pilot. Focus of this paper, however, is to elaborate further only one of the 5 VSs i.e. use of machine learning for "Evergreen Production Forecast for Field Development Plan (FDP) optimization and Locate the Remaining Oil (LTRO)".
An Improved HLD-NAC Model for Microemulsion Phase Behavior Study
Authors: Bu Xingang , Han Ming , AlSofi Abdulkareem , Fuseni Alhasan
Published: March 2022

Microemulsion phase behavior studies are essential for screening surfactants for improving oil production. The paper presents a modified Hydrophilic-Lipophilic Deviation – Net Average Curvature (HLD-NAC) model to explicitly express the solubilization ratio with respect to a newly defined inherent parameter representing surfactant properties. It also provides a workflow to extract the critical parameters from experimental results for numerical simulation of a chemical flooding process. The equations were derived to calculate the window of Winsor Type III microemulsion. The HLD-NAC model was improved to make the solubilization ratio explicitly expressed with the inherent parameter composed of head area (as), tail length (L) and molecular weight of the surfactants (Mw). An innovated workflow was developed to integrate the microemulsion phase behavior scanning results with the HLD-NAC model. The HLD-NAC model was validated with experimental data of various surfactant formulations.

The inherent parameter was applied in the improved HLD-NAC model, making it efficient for modeling microemulsion phase behavior scanning. The data of solubilization ratio and phase volume fraction were well fit in the model without needing to know the details of surfactant properties. This simplified the input of HLD-NAC parameters and made the output more accurate. The HLD-NAC model was successfully validated by experiments with various formulations including surfactant with alcohol, surfactant mixtures, and sodium carbonate-surfactant mixtures. By automatically obtaining the inherent parameter, the improved HLD-NAC model provides a promising application of microemulsion phase behavior in numerical simulation of chemical flooding. The HLD-NAC model is modified by defining an inherent parameter from experimental results of microemulsion phase behavior scanning. This makes it applicable to generate the solubilization ratio parameter for numerical simulation of chemical flooding.
The Role of Polymer on Surfactant-Foam Stability During Carbon Dioxide Mobility Control Process
Authors: AlYousef Zuhair , Swaie Othman , Alabdulwahab Amin , Kokal Sunil
Published: March 2022

The in-situ generation of foam is one of the most promising techniques to solve gas mobility challenges in petroleum reservoirs and subsequently improve the volumetric sweep efficiency. The stabilization of foam at reservoir conditions is a major challenge. The harsh reservoir conditions, such as high temperature, high brine salinity, together with surfactant adsorption on the rock may result in unstable foam and, consequently, poor sweep efficiency. Foam additives, such as polymers, might help strengthen the physical properties of foam film and improve foam stability. This work evaluates the effectiveness of a polymer on enhancing CO2-foam stabilization at harsh reservoir conditions.

Static and dynamic foam tests were conducted to evaluate the role of polymer on foam stability. Three foaming surfactants were used to assess the ability of the polymer on enhancing foam stabilization. The static foam tests were conducted at conditions similar to reservoir conditions using test tubes. Foam column, and foam life were measured to evaluate the role of the polymer on foam stabilization. Foam viscosity in absence and presence of the polymer was measured using foam rheometer apparatus. The dynamic foam tests were conducted to assess the ability of tested materials to generate viscous foams and also measure the CO2 mobility in porous media using a coreflooding system. The mobility reduction factor (MRF) was measured at high pressure and high temperature (HPHT) conditions, 3200 psi and 100°C.

The static foam tests and foam rheology measurements indicated that the addition of the polymer enhanced foam stability as a result of increasing the bulk viscosity of the aqueous solutions. The results found that the foam life increased with the polymer concentration. However, the increase of polymer concentration makes the solution very viscous, hence, the foam generation becomes challenging. The dynamic foam tests showed that the foam generated in absence of the polymer was able to reduce the CO2 mobility 13 fold. However, the addition of the polymer resulted in higher pressure drops during CO2 floods, more resistance to gas flow and, therefore, lower gas mobility compared to that obtained with surfactant alone. The addition of the polymer reduced the CO2 mobility 50 fold. This higher reduction in the CO2 mobility as a result of adding the polymer can be attributed to the effectiveness of the polymer in improving the foam stabilization and prolong the life of generated foam.