bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the Use of CO2 as a Hydraulic Fracturing Fluid for Water Sustainability and Environmental Friendliness
Authors: Fakher Sherif , Fakher Abdulaziz
Published: October 2021

Hydraulic fracturing is the process by which many unconventional shale reservoirs are produced from. During this process, a highly pressurized fluid, usually water, is injected into the formation with a proppant. The fracturing fluid breaks the formation thus increasing its permeability, and the proppant ensures that the formation remains open. Although highly effective, hydraulic fracturing has several limitations including relying on a highly valuable commodity such as water. This research investigates the applicability of carbon dioxide as a fracturing fluid instead of water, and studies the main advantages and limitation of such a procedure. The main properties that could have a strong impact on the applicability of carbon dioxide based hydraulic fracturing are studied; these factors include carbon dioxide properties, proppant properties, and reservoir rock, fluid, and thermodynamic properties. This research aims to function as an initial introduction and roadmap to future research investigating the applicability of carbon dioxide as a fracturing fluid in unconventional oil and gas reservoirs.
Evaluation of Nanofluids for Selected Malaysian Oilfields with Limited Cores: A Rapid Test Approach
Authors: Hendraningrat Luky , Majidaie Saeed , Che Mamat Che Abdul Nasser Bakri Bin , Razali Norzafirah Binti , Chien Chee Sheau , A Rasid Shahrul Aida Binti , Tewari Raj Deo , Kechut Nor Idah Binti
Published: October 2021

As an emerging technology, nanoparticle offers advanced benefits to be used as a novel improved oil recovery method. The nanoparticle has a much smaller size than pores of rock that can penetrate deeper in the reservoir and it is easily functionalized to change the wettability of rocks. However, the synthesize and screening process of nanofluids will be a laborious task and need a long-term period and numerous cores at rock-fluid tests. It would be a big issue if the research period is short and native cores are limited or even unavailable. This paper presents a rapid test approach to evaluate nanofluids for a Malaysian oilfield with limited cores.

Numerous nanofluids: nanopolymer and nanosurfactants, were evaluated using crude oil from a selected oilfield. Rapid measurement tests are proposed based on a parallel bottom-up approach from contact angle, thermal stability, and interfacial tension (IFT) measurement with at reservoir temperature conditions. Glass plate was initially used as the solid media for optimization of nanofluids concentration. Once this is ascertained then it can be used for further analysis on limited native core slab. Rock mineralogy, fluid rheology, and characterization were also determined. The fluid-fluid and rock-fluid measurements were repeated to ensure consistency of results and to estimate deviation in measurements.

Based on a rapid test approach, it was observed that the screening process only took several days instead of months to select suitable nanofluids and glass plates that could be used in the screening process to reduce consuming cores for oilfields with a limited core. A series of glass plate experiment showed consistent results with the core slab. It was observed that dynamic optical contact angle using can achieve steady conditions for approximately half an hour. It was also observed that both the glass plate and replicate core slab show consistency of wettability alteration trend and benefits of multiple runs can observe how big the deviation of measurement. As predicted, all nanofluids can alter the rock wetting behavior. A decreasing contact angle showed that the solid media was rendered to be more water-wet, which implies better oil displacement due to residual oil saturation reduction. Surfactant grafted nanoparticles have given marginal effect on IFT reduction at a certain concentration and achieved steady in less than an hour. These results showed the most potential rapidly for further analysis on coreflooding experiments.

The rapid test approach can evaluate and screen nanofluids for detailed coreflooding experiments. This approach readily applies for uncored or limited cores and limited research period.
High-Temperature Stable Specific Enzyme for Guar Polymer Based Fracturing Fluid Degradation
Authors: Abdelrahim Mumin Abdalla , Ghosh Dr. Bisweswar , Belhaj Dr. Hadi , Ghosh Debayan
Published: October 2021

Hydraulic fracturing, commonly referred to as fracking, is a widely used technology to enhance the productivity of low-perm reservoirs and the aqueous-based fracturing fluids use guar as the rheology builder. Residual polymer layer over the fractured surface results in a reduced matrix to fracture permeability, causing reduced well productivity. This research aims to develop a specialized mannanase enzyme and evaluate its efficiency in degrading linear and cross-linked guar polymer gel as a function of time, temperature, and breaker concentration, to enhance the effectiveness of the fracturing process and yielding higher production. The study begins with developing high-temperature stable mannanase using "protein engineering" tools to minimize denaturation at high temperatures and the underlying formation chemistry, followed by optimization of polymer, crosslinker, and breaker concentration through the measurement of rheological properties at moderate to high temperature. Initial studies were conducted using HT-HP filter press and filter papers as porous media for visual inspection of polymer cake dissolution efficiency. Final conclusions were drawn from the simulated coreflooding studies, wherein the injection and production return permeabilities were investigated on post-fracture and enzyme-treated cores, where the breaker was mixed with the frac fluid applied once the frac fluid is in place. The thermal stability of the enzyme breaker vis-à-vis viscosity reduction and degradation pattern of linear and cross-linked gel observed from the break test showed that the enzyme is stable up to 250 °F and can reduce viscosity by more than 1800 cp (99% breaking ability).
Innovation in Managing Leak Repair and Crude Oil Lifting Schedule to Respond to Pipeline Leak in Offshore Terminal System
Authors: Firmansyah Ferry , Satriawirawan Adit , Wisnudarto Aryo
Published: October 2021

Offshore terminal usually performs crude oil lifting process regularly every 7-8 days. However, three repetitive leaks in crude oil subsea pipeline 36" MOL SPM-1 to SPM-2 occurred in the offshore terminal area had stopped the natural oil lifting process. Due to complex conditions, leak repair needs a longer duration and some future crude oil lifting schedules facing cancelation possibilities.

By simulating the leak parameter, more than 60 bbl. of crude oil would release from the leaking pipeline in 48 hours crude oil lifting operation. An innovative approach is built by designing a new tool to contain oil spills from the source using a pyramid shape tank and safely transport to the temporary storage tank on the diving vessel to keep crude oil lifting process execution still possible to hold while the subsea pipeline repair by installing subsea clamp is undergo.

New tools have successfully eliminated oil spill spreading during crude oil lifting takes place schedule. Six crude lifting schedules have been safely delivered with nearly 30,000 liters of crude oil spill have been evacuated and transferred back to processing facilities. Further implementation would possibly be held in pipeline preservation program and diver less application, which can increase leak response time.
Heavy Oil Polymer Pilot with Active Bottom Water Drive – A Success Story
Authors: Dadlani Hitisha , Jain Gaurav , Saikia Sabyasachi
Published: October 2021

Bechraji is one of the major fields of heavy oil belt of Mehsana Asset in Western India. It contains heavy oil with average viscosity of ~270cp at reservoir temperature. During the early phase of production, high viscosity led to viscous fingering which resulted in sharp rise in field water cut to ~80%.

Polymer flood in heavy oil has received significant attention after the numerous success across the globe namely, Marmul Oman, Bohai Bay offshore China and Pelican lake Canada fields. Screening studies were conducted followed by comprehensive laboratory evaluations of chemical flood potential which identified it as suitable process. Thus, a normal five spot pattern pilot testing was planned to understand the role of chemical EOR methods in the ultimate development strategy for the Bechraji.

Comprehensive monitoring and quality control procedures were being followed to ensure smooth operations. Pressure surveys, tracer surveys, detailed produced fluid analyses and tests for monitoring the quality of injected fluids were all performed routinely. This paper deliberates the operational aspects of polymer flood, quality control and monitoring program followed, challenges faced and results of polymer flooding.
Novel Approach of Sucker Rod Pump Unit Balance Determination and Monitoring
Authors: Aryadi Yuzar , Hidayat Azis , Lazuardi Hilman , Isnanto Syahroni , Ariwibowo Bonni , Muklas Aliefiyan Nursanda , Fathurachman Ahmad , Gema Ramadhan Ghalib Bima , Kamil Maulana Insan
Published: October 2021

SCADA optimization platform is implemented to monitor and evaluate well performance. For Sucker Rod Pump, SCADA Optimization Software can be used to monitor the unit balance and gearbox torque. In some ways, not all required well configuration data for SCADA Optimization Software to do a calculation of counterbalance torque (CBT) for pumping unit balance and gearbox torque evaluation are available. Standard field Counterbalance Effect (CBE) measurement might be performed to calculate the CBT value. However, this standard procedure is limited to well that run on balance condition. For well with unbalance condition, the measured CBE needs to be adjusted by a correction factor which the equation will be presented in this paper. The corrected CBE value from the new equation is then inputted to the SCADA Optimization software to perform day-to-day real-time monitoring of pumping unit balance and gearbox torque.

Derivation of the CBE correction factor equation is presented. Validation upon this new equation is performed by comparing the result with electrical measurement on the pumping unit motor. Using the calculated CBT from the new equation, SCADA Optimization Software performs gearbox torque and pumping unit balance analysis based on every collected dynamometer card.

Calculated CBT from the new equation provided results in gearbox torque distribution pattern that match with measured electrical parameter distribution along the stroke. This CBT value assists SCADA optimization software to calculate pumping unit balance and gearbox torque. Alarm in the SCADA optimization software that coming from an anomaly on pumping unit balance and gearbox torque help operator to do preventive maintenance so that pumping unit component especially the gearbox could have longer run life.
Access to Environmentally Friendly Energy and Capacity Building for Communities in the 3T Frontier, Outermost and Least Developed Region Through the Corporate Social Responsibility Program
Authors: Wibowo Agung , Doloksaribu Anton Humala , Rahman Aditya Cahya Kurnia
Published: October 2021

PT. Pertamina EP Asset 5 Tarakan Field (PEP Tarakan Field) is one of the upstream oil and gas companies that play an active role in improving the community's welfare around its operational area through social responsibility programs. Through renewable energy access, community empowerment was one of the activities carried out in Tepian Village, Sembakung District, Nunukan Regency, North Kalimantan Province. This activity aimed to provide an alternative energy source that is environmentally friendly and more cost-effective to help reduce the cost of living for the underprivileged communities in the village.

The concept of implementing the social responsibility program adapted by Tarakan Field consists of 4 elements: Organizing Identity, Organizing Transactivity, Organizing System, and Organizing Accountability. The program implementation began with a social mapping that includes data on beneficiaries of the diesel generator conversion program into a Solar-cell Home System. Then, conducted a Focus Group Discussion with village officials and related agencies to listen to suggestions and input on this program. Approximately 30 housing units/140 people from the pre-prosperous group became the beneficiaries of this program. Several residents were also given training in maintenance skills of the Solar-cell Home System unit, following the standards and procedures implemented by the company. Periodically, monitoring is also carried out to see how far the beneficiaries feel the program's impact. In addition, the implementation of monitoring was also helpful to detect obstacles encountered in program implementation so that improvements could be made immediately. Evaluation is carried out every year and at the end of the program mentoring period to see how far the beneficiaries feel the program's impact. Monitoring and evaluation carried out by Tarakan Field also involved other agencies such as academics to involve various disciplines.

After this program was implemented, there was a 50% living costs reduction of the underprivileged groups because they no longer needed to buy diesel to turn on the diesel generator as a source of electrical energy. In addition, there is a reduction in carbon emissions from diesel generators and a decrease in noise levels in the environment around the village.

This social responsibility program also supported the government's third point in the Nawacita programs: to build Indonesia from the margins and support the program to achieve the seven sustainable development goals (SDGs), namely clean and affordable energy. In 2017, this program became a trigger for the Ministry of Energy and Mineral Resources Republic of Indonesia assistance program in the form of a Solar-cell unit with a capacity of 75 kWp, which can accommodate the needs of the entire house network in Tepian Village.
Remote Sensing in Oil Spill Handling in Offshore North West Java
Authors: Ligafinza Audra , Sajjad Farasdaq Muchibbus , Jabbar Mohammad Abdul , Fatmawati Anggia , Wirawan Alvin Derry , Suganda Wingky
Published: October 2021

During the blowout event, it is critical to track the oil spill to minimize environmental damage and optimize restoration cost. In this paper, we deliver our success story in handling oil spill from recent experiences. We utilize remote sensing technologies to establish our analysis and plan the remediation strategies. We also comprehensively discuss the techniques to analyze big data from the satellites, to utilize the downloaded data for forecasting, and to align the satellite information with restoration strategies.

PHE relies on its principle to maintain minimum damage and ensures safety by dividing the steps into several aspects of monitoring, response (offshore and onshore), shoreline management and waste management. PHE utilizes latest development in survey by using satellite imaging, survey boat, chopper and UAV drone. Spill containment is done using several layers of oil boom to recover oil spill, complemented with skimmers and storage tanks. PHE encourages shoreline remediation using nets and manual recovery for capturing oil sludge.

Using this combination of technologies, PHE is able to model and anticipate oil spill movement from the source up until the farthest shoreline. This enables real time monitoring and handling, therefore minimum environmental damage is ensured. PHE also employs prudent engineering design based on real time field condition in order to ensure the equipment are highly suited for the condition, as well as ensuring good supply chain of the material availability.

This publication addresses the first offshore blowout mitigation and handling in Indonesia that uses novel technologies such as static oil boom, satellite imaging and integrated effort in handling shoreline damage. It is hoped that the experience can be replicated for other offshore operating contractors in Indonesia in designing blowout remediation.
Study on Enhanced Oil Recovery Using Microorganism Generating Foam in Presence of Nanobubbles
Authors: Ito Miu , Sugai Yuichi
Published: October 2021

Both high cost and environmental load of surfactant are issues to be solved in foam EOR. Moreover, it is difficult to control the injection of surfactant and gas so that the foam is generated in only high permeable zones selectively in oil reservoir. The authors have found a foam generating microorganism and hit upon an idea of the microbial foam EOR which makes the microorganism do generating foam in oil reservoir. The mechanism of the microbial foam generation and culture condition suitable for the foam generation were studied in this study.

A species of Pseudomonas aeruginosa was used as a foam producer in this study. It was cultured in the medium consisting of glucose and eight kinds of minerals at 30 °C and atmospheric pressure under anaerobic conditions. Because P. aeruginosa generally grows better under aerobic conditions, the microorganism was supplied with oxygen nanobubbles as the oxygen source. The carbon dioxide nanobubbles were also used as a comparison target in this study. The state of foam generation in the culture solution was observed during the cultivation. The surface tension, surfactant concentration, protein concentration, polysaccharides concentration and bacterial population of the culture solution were measured respectively.

The foam was started to be generated by the microorganism after 2 days of cultivation and its volume became maximum after 3 days of cultivation. The foam generation was found in the culture solution which contained both oxygen nanobubbles and carbon dioxide nanobubbles whereas little foam was found in non-nanobubbles culture solution. The foam generation found in the culture solution containing carbon dioxide nanobubbles was more than that in the culture solution containing oxygen nanobubbles. Both gas and protein concentration increased along with the formation of the foam whereas surfactant and polysaccharides were not increased, therefore, the foam was assumed to be generated with gas and protein which were generated by P. aeruginosa. It was found that the carbon dioxide nanobubbles were positively charged in the culture medium whereas they were negatively charged in tap water through the measurement of zeta potential of nanobubbles, therefore, the carbon dioxide nanobubbles attracted cations in the culture medium and became positively charged. Positively charged carbon dioxide nanobubbles transported cations to the microbial cells of P. aeruginosa. Among cations in the culture medium, ferrous ions are essential for the protein generation of P. aeruginosa, therefore, the positively charged carbon dioxide nanobubbles attracted ferrous ions and transport them to the microbial cells, resulting the growth and metabolism of P. aeruginosa were activated.

Those results suggest that the microbial foam EOR can be materialized by supplying the microorganism with carbon dioxide nanobubbles or ferrous ions.
Automation & Digitalization Implementation – A New Normal in Oil & Gas Industry: A Success Story
Authors: Mario Cio Cio , Pramana Harris , Eviany Ameria , Nugrahanto Anang , Nasrudin Nasrudin , Murtani Anom Seto
Published: October 2021

Nowadays automation and digitalization in oil & gas industry have become a new normal practice to replace traditional workflows. The implementation of automation and digitalization is driven by the need to automate the repetitive and low-cognitive tasks, so it allows engineers to spend more time on high-cognitive and high-level analytical evaluations or studies, and to finally lead up to smarter decisions. One of the solutions is by developing and implementing "fit for purpose" automation tools which consist of various data analytics inside the tools.

Saka Energi Indonesia, as the operator of Pangkah PSC, has developed and implemented automation and digitalization in Ujung Pangkah field. Located in northern side of East Java, the field's reservoir consists of multi-layered carbonate oil and gas zone, which is being produced through horizontal and directional wells. Solutions of automation and digitalization have been developed for the Ujung Pangkah field to minimize loss opportunity, increase oil production and reduce the field decline rate. With some collaboration efforts from Subsurface, Operation and IT Department Team, some automation tools have been developed and implemented in Ujung Pangkah Field, which are as follows:

Exception Based Surveillance (EBS) tool: An automation tool to identify real-time well problems & opportunities. Auto Gas Lift Rate Allocation (GALAA) tool: An optimization tool to automate gas lift rate allocation. SAKA Well Opportunity, Register, Define and Select (SWORDS): An automation tool to evaluate well opportunity portfolio. Well Model Update Automation: A tool to update well model automatically for every individual well.

By implementing the automation solutions, various repetitive tasks can be completed significantly faster and more efficiently. Saka engineers have more time to perform high-cognitive analytical evaluations on other technical areas. Ujung Pangkah field oil production decline rate has been successfully decreased from 21%/year to 8.6%/year after the automation solutions have been implemented in 2018.

Ujung Pangkah success story of automation & digitalization implementation will be used as a reference for managing other Saka assets in different fields. The new automation solutions are a faster and a more efficient way of optimizing existing field production and it will give positive impacts exponentially with increasing well numbers.
Study on Fracture Conductivity of Mahu Sandy Conglomerate Tight Oil Reservoir
Authors: Yang Liu , Gao Jingwei , Chang Shilei , Wan Qianbing , Liu Canhua
Published: October 2021

Objectives/Scope: Effective development of tight oil and gas depends on the generation of artificial fractures, and continuous and efficient development of tight oil and gas requires the use of proppants to maintain the diversion effect of artificial fractures. At present, the microscopic mechanism of damage to fracture conductivity of sand conglomerate reservoir is not clear.

Methods, Procedures, Process: Taking the sandstone conglomerate in Mahu sag as the research object, the experimental study on the fracture conductivity of the sandstone conglomerate in Mahu sag is carried out. First, the stress sensitivity analysis of the sandstone conglomerate is performed on a pore scale using a self-made permeability measurement method, then, the fracture width, pressure and flow rate are measured under the condition of fracture scale to analyze the change law of conductivity during fracturing fluid injection.

Results, Observations, Conclusions: The results show that the permeability of gravel decreases with the increase of confining pressure, and the stress sensitive damage is strong. After a cyclic loading condition, permeability will not recover to the initial value, causing irreversible damage to the pore and roar. As the fracturing fluid continues to be injected, a large amount of proppant becomes embedded in the fracture and leads to a decrease in conductivity. The whole diversion curve can be divided into two stages. In the first stage, the diversion damage is great, and in the second stage, the diversion damage decreases somewhat. The damage of conductivity is closely related to the content of clay minerals.With the increase of clay mineral content, the conductivity damage rate increases rapidly, especially the existence of illite and Aimonite mixed beds can significantly improve the conductivity damage rate.

Novel/Additive Information:The results provide a solution for the optimization of proppant concentration, the improvement of tight oil production and the study of gravel diversion damage mechanism in the Mahu area.
Additive Scale Removal Based on Noncorrosive Organic Acid for Handling Silica and Carbonate Scale in Oil and Gas and Geothermal Wells
Authors: Pasarai Usman , Wahyudi S. Panca , Haans Arie , Widiantara IGN , Saroyo Budi
Published: October 2021

The silica and carbonate scale that forms along the production pipeline is a significant problem in the oil and gas and geothermal industry because it disrupts production operations. Silica and carbonate scales on the inside of the pipe cause blockage of flow and an increase in pressure. Failure of downhole settlement equipment will reduce the production capacity of the well, and the maintenance burden will increase.

The main objective of this research is to test the reactivity of an environmentally friendly non-corrosive organic acid system based on vegetable fatty acids and carbohydrates with high dissolution efficiency for the treatment of silica and carbonate scales in geothermal and oil and gas fields. This paper provides information on laboratory analysis in terms of analysis of the composition of scale samples obtained through XRD analysis, acid system developed testing for dissolution efficiency at 50°C and 100°C for 1 hour, compatibility and stability testing, and testing the corrosive impact on coupon metal AISI CS-1019 samples at 100°C for seven days in a closed aging cell.

Testing the concentration of the new organic acid system in high dissolution efficiency and low corrosion effect was carried out through laboratory-scale studies before being applied to field-scale operations. The results showed that the dissolution efficiency of the scale sample against the developed organic acid system (100% concentration) at 50 and 100°C for 1 hour showed reactive effect. Reduction rate of silicate-07; silicate-29; silicate-L1; silicate-KB1; carbonate-A3 at 50°C were 7.825%; 3.823%; 6.177%; 2.014%; 8.211%, and at 100°C were 12.884%; 0.631%; 15.047%; 0.103%; and 32.909%. The newly developed organic acid system demonstrates stability and compatibility with formation waters with low formed solids, and it has a pH of 6. The results of the corrosion rate test were carried out without an inhibitor at 100°C for seven days and gave a yield of 77.340 mils per year, while other commercial additives gave a yield of 2,525.120 mils per year. The new eco-friendly organic acid system has a good effect in helping dissolve silica and carbonate scales, safe for production equipment, and lowers high maintenance costs.

Keywords: Organic Acid Scale Remover, Silica and Carbonate Scale, Environmentally friendly
A Numerical Simulation Study of CO2 and N2 as Cushion Gas in an Underground Gas Storage
Authors: Tang Kang , Liao Xinwei , Zhao Xiaoliang , Li Haojie , Li Xiaoxiao , Wang Xiaochen , LI Jiehan
Published: October 2021

Underground gas storage (UGS) is a beneficial economic method of compensating for the imbalance between natural gas supply and demand, which is currently considered an important part of the gas chain. To reduce the capital investment of gas storage, the use of alternative gases as cushion gas is a good choice. However, the mixing of different gases in the UGS challenges the application of alternative gases(N2and CO2) as cushion gas. In this paper, we first conduct the thermodynamic analysis of two alternative gases, namely, N2and CO2. The feasibility of these two gases as cushion gas is discussed. Secondly, a gas storage located in Eastern China is selected. Based on the physical properties of the reservoir, a simulation model with coupled diffusion mechanism is conducted. Finally, the effect of molecular diffusion, gas category and ratio on the dynamic operation of UGS is studied. In addition, the CO2storage capacity under different operating parameters was also analyzed. This study provided a scientific basis for the efficient operation of UGS and the geological storage of CO2.
Challenging Horizontal Well Abandoned with Innovative Plug Setting Technique and Tailored Slurry Design
Authors: Simmadorai Dinesh , M Ariffin M Syafiq , Patil Mayank , Franke David , Noh Aizat , Lau Chee Hen , Kumar Avinash Kishore
Published: October 2021

Setting multiple plugs across a horizontal well can be a challenge. One way to do this is using the "pump and pull" methodology to achieve the objectives set out by the project team. Tailoring of the cement slurries and the execution of cementing operations for the successful deployment of multiple cement plugs using this method to achieve a dependable barrier across a horizontal reservoir section will be reviewed and discussed. A development well in Malaysia lost a bottom hole assembly (BHA) in their 8.5" hole section. This resulted in the requirement to abandon a long horizontal section along with the requirement to spot a 2,100 ft continuous cement plug on top of the BHA to abandon the well.

The main challenge for setting a cement plug across a horizontal section, is cement slumping and stuck pipe, which might result in repeating cement plug jobs or non-productive time having a negative impact on well economics. To achieve isolation objectives in the first attempt, this long continual plug was broken up amongst four smaller individual plugs "stacked" on top of each other. The first 3 plugs were designed to each be 600 ft in length followed by a 340 ft plug. To avoid cement slumping, a cement support tool was deployed above the BHA before the first plug in the horizontal section. The first three plugs were placed in the horizontal open hole section and the fourth plug was placed at an inclination of 75 degrees, all using the "pump and pull" method.

The pump and pull method is a common practice for worker operations with coil tubing and this similar technique can be applied in ERD drilling operations to aid in the homogeneous and accurate placement of cement plugs. However, for this job, the pump and pull placement method was preferred to aid in the homogenous and accurate placement of cement slurry through the horizontal open hole section. Detailed job calculations, the slurry design which was tailored for this application along with detailed operational procedures which resulted in the successful placement of all plugs on the first attempt under challenging well conditions will all be discussed.

The approach utilized here resulted in the successful placement of a 2,100 ft continuous plug which isolated the BHA and saved the project valuable rig time. Similar approaches can be used in other areas to achieve successful results in first attempts to help well economics.
Hanging Screen Evaluation to Unlock Marginal Sandy Reservoir: Case Study of Peciko Gas Field, Indonesia
Authors: Hidayat Danny , Marindha Rantoe , Nugroho Triantoro Ade , Hidayat Reyhan , Rusdi Runi Kusumaning
Published: October 2021

Peciko Field currently produces gas from multilayer sand-prone shallow reservoirs. Therefore, it needs sand control method to unlock these marginal reservoirs through low-cost intervention. Hanging screen has been reviewed as an alternative solution to minimize sand control cost while maintaining its robustness to maximize the recovery. This paper will present and evaluate the hanging screen installation and performance from subsurface to surface elements in Peciko field.

Hanging screen implementation in Peciko will be evaluated in terms of ease of installation to its performance during production phase. Peciko wells are equipped with real-time monitoring system including Acoustic Sand Detector. Therefore, sand problems could be easily identified. Any indication of screen failure will be confirmed by checking the surface equipment like chokes and intrusive probes. Further intervention to retrieve the screen and perform visual check at surface can be executed to extend the verification. Filter size, placement method, clean-up, and sand sieve result will be gathered to identify the root cause and determine the best method to apply hanging screen as reliable sand control method.

Nine installations in 2019 conclude that screen plugging, liquid loading, and combination of both are main issues in production phase. With three plugging cases from well Fx and E2x, it was found that excessive drawdown pressure triggers high gas velocity in perforation tunnel and causing excessive sand production that plugged the screen. These cases also prove that self-unloading by choke movement can lead to plugging if the drawdown pressure and gas rate are not monitored carefully. Commingle production in Ax becomes an issue in lifting performance when reservoir pressure declines and liquid was produced from several reservoirs. Limiting drawdown pressure gives smaller gas rate to lift the liquid and make the well died from liquid loading easily. Massive sand production in well E2x and E2y cause an increase in Top of Sediment (TOS) and lead to inaccessible screen even with multiple bailing attempts. A series of screen design, choke configuration, proper clean-up and continuous monitoring are critical steps to be performed prior and after screen installation to maintain production lifetime. With average stakes of 0.2 Bcf per well, hanging screen has proven to produce 67% of the well reserves in shallow reservoirs. This value creation led to the conclusion that hanging screen is an economically-feasible-sand control method to be implemented in Peciko.
High Shut-in Pressure: Good News or Bad News? Maximising Value through Limited Data
Authors: Sutoyo Handita Reksi Dwitantra , Nurhajj Diniko , Anindyajati Anak Agung Iswara , Febrianto Dwi Hudya , Kristianawatie Nova
Published: October 2021

Early production of gas reservoirs is usually associated with a volumetric gas driving mechanism with no water production. Aquifer activity is minimal as well during the early life of the reservoir. In this paper, we will discuss about the good engineering practices based on several shut-in pressure data to observe and maximize marginal gas field value. We will also discuss about the possibility of water drive behavior in this field.

Shut-in pressure data plays an important role in determining the in-place and reservoir dynamics of the gas reservoir. High shut-in pressure usually indicates high gas reserves. On the other hand, it shows a very strong water drive existence. The study takes place on a sandstone gas reservoir with an abnormal pressure regime on it. Production performance was then analyzed using the rate transient analysis (RTA) to determine its properties and gas in place and crosschecked with shut-in pressure data. From these steps, we can determine the trend of both static and flowing material balance (FMB) analysis to predict the reservoir dynamics.

During the early life of production, it is clear that volumetric reservoir plays an important role in the reservoir dynamics since it produces no reservoir water. However, after 1 year of production, it starts to produce reservoir water. Monitoring starts when the first shut-in pressure shows a quite unexpected value. It puts a sense of both high gas reserves and aquifer activity. After applying all the pressure and production data on FMB and p/Z plot, it shows that both high gas reserves and aquifer activity exist in this field. The results of this study change the development strategy of this field, preventing doing major investment on high capital expenditure (CAPEX) with low results due to high aquifer activity. We can conclude that good reservoir monitoring and analysis combining several analytical methods can enhance our insight into reservoir dynamics.

Combining FMB and p/Z, geologist starts to compare aquifer volume based on geological data and found to be similar with the results coming from analytical data. 3D reservoir simulation also confirms similar results based on those analyses.
Robust Screening Criteria for Foam-Assisted Water-Alternating Gas FAWAG Injection
Authors: Kechut Nor Idah , Groot Johannes A.W.M , Mustafa Mohd Azlan , Groenenboom Jeroen
Published: October 2021

Foam-Assisted-Water-Alternating-Gas (FAWAG) injection has been proposed to improve the inherent unfavorable mobility ratio of gas and liquid in WAG process. The foam reduces gravity override and gas channeling as to improve volumetric sweep efficiency and thus oil recovery. There are still a lot of uncertainties yet to be understood in foam dynamics, surfactant adsorption, and foam stability when contacting oil, which impact the actual foam propagation into the reservoir. Although some insights are gained from laboratory and field experiments, the performance, and design of the injection strategy and facilities as part of the field development of FAWAG is not trivial and field data is sparse.

Extensive laboratory experiments and simulation studies are necessary to de-risk enhanced oil recovery (EOR) application, but these processes are time consuming and expensive. For this reason, a screening study is normally conducted to increase the possibility of selecting high potential candidates prior to embarking on the detailed feasibility studies. Unfortunately for FAWAG, the screening criteria are not readily established nor commonly available in commercial screening tools unlike for other matured EOR methods, largely contributed by the limited database on FAWAG field implementations worldwide.

This paper presents a robust FAWAG screening tool which accounts for important reservoir properties, uncertainties in foam model parameters, as well as various reservoir conditions of oil and gas production and injection plans. The FAWAG process is modelled from the assumption of local equilibrium of foam creation and coalescence using an Implicit Texture model. Relevant foam scan experiments/steady state coreflood data were analyzed to derive parameters that characterize foam dynamics.

The sensitivity study in this paper ranks and identifies the main risks and opportunities for the FAWAG process, quantifies the reliability of the model and increases the understanding of the effective dynamic behaviour. The sensitivity study was the basis for the development and validation of a proxy model by design of experiments. The screening tool employs this proxy model to generate immediate screening results without the need to run additional simulations. The screening tool was further validated with upscaled experimental data. A set of prediction results on the range of oil recovery for numerous plausible field scenarios was established; these screening criteria will be used as the basis for high-level decision making.
A Novel Chemical Treatment and Well Completion Strategy to Prevent Scale and Production Losses in Shushufindi Aguarico Field
Authors: Paredes Monica Paulina , Marques da Silva Luciano Bravo , Egas Lucia Del Rosario , Endara Edison Atahualpa , Escalona Pedro Luis , Maulidani Oki Ari , Pineda Alexander José , Estevez Diego Renato , Guaman Juan Carlos , Carrion Johana Jackeline , Freire Carola Judith , Villamar Fausto Alexis
Published: October 2021

In this case study, EP Petroecuador and Consorcio Shushufindi evaluate a chemical treatment and completion strategies to reduce the extensive impact of bottomhole scale deposits on oil production, electrical submersible pumps (ESP) run life, and operating costs of wells completed in the high-scaling tendencies reservoir. The positive impact on oil production optimization resulting from these strategies will also be discussed and the advantages, lessons learned, and constraints of this work.

Conventionally, corrosion and scale chemical inhibitors are deployed through capillary lines; this method is effective up to the pump depth but does not prevent deposits at the perforations or at the lower completion and near wellbore. Rapid production decline or complete loss of production is observed, requiring costly well interventions. Laboratory analysis and evidences from the interventions show that lower T-sand fluids present a high-scale tendency at the bottomhole; therefore, a process to identify candidates and deploy chemical treatment in the rathole to prevent scale deposits was defined and proved. The technology selected was encapsulated scale inhibitors (microcaps).

Based on the process, two wells were selected from a portfolio of 12 wells that match the criteria to apply the method to deploy the technology. The following observations were drawn: -Calcium carbonate (CaCO3) is the most common scale-ESP parameters and production surveillance are essential for early detection of problems associated with scale deposits at bottomhole-The action of microcaps and the installation of a pipe tail below the ESP base sensor allowed to deepen the continuous dosage of scale inhibitor and has already doubled the run life of the ESP equipment, with direct savings on operations costs (approximately USD 240,000) in the short time and continue and can continue to yield more.-According to post workover (WO) production tests of the two candidates and the performance of ESP parameters, the application of this strategy made possible to restore the productivity indexes and sustain them over time. This leads to reduction in production losses of 310 BOPD or 60% of the actual production in the similar period before the treatment.-The microcaps can be applied and refilled through rig-less annulus-It is a low-cost solution for scale problems at bottomhole.

This document presents an analysis to reduce operating costs in wells that produce fluids with a high-scaling tendency at bottom hole, through an unconventional and low-cost strategy of chemical treatment from the sand face to the wellhead. This novel process and microcaps application can be used in wells in remote and difficult areas to service on a regular basis.
Designing a Successful MOOC – An Empirical Study of the Foreign Language Courses On a MOOCs Platform
Authors: Kuang Jia , He Lan
Published: October 2021

MOOCs have achieved great development in the last five to seven years. However, MOOCs present unique features of their own which distinguish themselves from the traditional classroom interaction. In this article, in order to find out the factors influencing the design of successful MOOCs, we examined the communication mode of MOOCs from the perspective of symbolic interactionism by combining the features of the communication mode of MOOCs as well as that of the traditional classroom interaction. Multiple linear regression analysis was conducted on 280 sample MOOCs from the foreign language courses category of a major Chinese MOOCs platform. The findings indicate that providing options for comprehension, providing options for self-regulation, coherence and temporal contiguity are the key factors for a successful design of MOOCs.
A Study of the Interaction of Ixabepilone As Anticancer Drug With Acetoxymercuric Fluorescein Reagent by Fluorescence Quenching Approach: A Validated Method
Authors: Salem Hesham , abdelaziz Amany , Gamal Aliaa , Sabaa Ramy El
Published: October 2021

A spectrofluorimetric approach has been developed and validated for determination of sulfur-containing drug; ixabepilone in raw powder, vials and human plasma. This approach studies the quenching effect of IXA on the fluorescence intensity of acetoxymercuric fluorescein (AMF) reagent at λem of 530 nm and λex of 500 nm. All the parameters that can affect the reaction as pH, AMF solution concentration, temperature, time and solvents were studied and optimized. The linearity range of the studied approach was 20-100 ng mL-1 with correlation coefficient of (r = 0.9998). The proposed approach was validated and approved regarding to ICH guidelines in terms of accuracy, precision, linearity, LOD and LOQ, with mean percentage recovery of 99.79 and RSE% of 1.64. The previously obtained resultes were already statistically compared with that of established reported methods indicating no significant differences in accuracy and precision. Finally, the proposed approach is easy, sensitive, and inexpensive so it is suitable for routine determination of IXA in raw powder, vials and human plasma with no need for any prior separation or sample extraction.
Comparison of Tibial Anatomical-mechanical Axis Angles and Patellar Positions Between Tibial Plateau Levelling Osteotomy (TPLO) and Modified Cranial Closing Wedge Osteotomy (AMA-Based CCWO) for the Treatment of Cranial Cruciate Ligament Disease in Large Dogs With Tibial Plateau Slopes Greater Than 30° and Clinically Normal Labradors Retrievers
Authors: Guénégo Laurent , Vezzoni Aldo , Vezzoni Luca
Published: October 2021

Background: The objective of this study was to evaluate tibial anatomical-mechanical axis angles (AMA-angles) and proximodistal and craniocaudal patellar positions following tibial plateau levelling osteotomy (TPLO) and AMA-based modified cranial closing wedge osteotomy (CCWO) in large dogs with tibial plateau angle (TPA) >30°, to compare these postoperative positions with those of a control group of healthy normal dogs, and to assess which procedure yields postoperative morphology of the tibiae and stifles that is most consistent with that of the unaffected group. This study also investigated whether the occurrence of patellar ligament thickening (PLT), which is commonly observed two months postoperatively after TPLO, is associated with misplacement of the osteotomy. A total of 120 dogs weighing more than 20 kg, 40 of which were control animals, were enrolled in this retrospective study. Stifles were radiographically evaluated preoperatively and postoperatively on the side with CCLR and on the healthy contralateral side and compared with clinically normal stifles. PLT was reassessed after two months.Results: Significant decreases in median patellar height ratio were found after both procedures (TPLO 0.24 (0.05–0.8); CCWO 0.22 (0.05–0.4)). The postoperative craniocaudal patellar position and the median AMA angle differed significantly among the groups (P=0.000) (TPLO 87.5% caudal to the AA and 3.12° (0.76–6.98°); CCWO 100% cranial to the AA and 0° (-1.34–0.65°); control group 5% caudal to the AA and 0.99° (0–3.39°)).At 8 weeks, PLT grade differed significantly in the two operated groups (P=0.000) (TPLO 40% 0–2, 20% 2–4, 40% >4; CCWO 98.8% 0).Conclusions: TPLO and AMA-based CCWO are associated with significant decreases in patellar height; however, the PLT results two months postoperatively differed between the two groups; the decrease in patellar height and PLT were independent of osteotomy position in the TPLO group. Compared to TPLO, CCWO results in reduced postoperative AMA angles and craniocaudal patellar positions that more closely resemble those of unaffected dogs, suggesting that the CCWO procedure allows us to better correct the caudal bowing of the proximal tibia that is often associated with deficient stifles in large dogs with TPA >30°.