bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Methodology for Total Gas Monitoring to Improve Well Safety Assurance
Authors: Shahini Edisa , Nonno Lamberto , Zanchi Augusto , Pozzovivo Vincenzo
Published: November 2019

At a time when maximizing operational efficiency is needed more than ever, advancements in data processing and analytical capacity may provide a sustainable path for uncovering hidden correlations and other insights from one of the basic roles and responsibilities of any surface logging services provider. This paper showcases a side-by-side comparison of two gas extraction devices and how they influence gas readings and, eventually, total gas measurement related to well control operations monitoring.

Although the trend analysis from gas reading values is imperative for pore pressure predictions and other classical readings, this paper negates its use for lower explosive limits (LEL) by using laboratory methods paired with a study in the field. The apparatus used to extract total gas in water-based mud was a constant-volume, constant-temperature and constant-flow system. The detector used to measure the total gas concentration was a flame-ionized detector (FID) system.

The influence of gas extraction devices on gas data is crucial for the determination of total gas. Conditions affecting gas readings have been explored at length, and they include gas extraction temperature, mud flow rates, gas flow rates, and drill rates (i.e., rate of penetration). Due to the development of analytical capacity, the extraction method and the analysis devices are compared in this paper.

Wellsite total gas monitoring, which usually provides common wellsite total gas values, has been heavily analysed regarding what it fundamentally represents. Total gas also helps operators to harness their data and use it to identify process safety indicators, as well as other environmental emissions applications.

Estimates of total gas concentration in the drilling fluid, as detected by a gas extraction device, can vary, based on the device type. This paper shows how the different extraction methodologies fit into well safety operations monitoring and process safety requirements to better evaluate and define new risk communication and safety practices in the industry.
Can HVFRs Increase the Oil Recovery in Hydraulic Fractures Applications?
Authors: Ellafi Abdulaziz , Jabbari Hadi , Ba Geri Mohammed , Alkamil Ethar
Published: November 2019

In unconventional reservoirs, such as Bakken Fm, the stimulation application is the required method to develop and produce economically from this vast reserve. However, the production process is still only through primary depletion mechanism with low recovery factor in ranging of 3-5% due to sharp decline in oil production by depletion in natural fracture networks as well as unsuccessful implementation hydraulic fracturing design. This paper aims to investigate the application of HVFRs with surfactant in high TDS condition to enhance Bakken oil wells production performance using an integral methodology between 3D/2D Pseudo hydraulic fracturing simulator and numerical reservoir simulation. Four types of fracturing fluids as follows: Linear Gel, HVFR-A (mixed with freshwater), HVFR-B (mixed with produced water plus surfactant as additives), and HVFR-C (mixed with produced water) were tested using an integral approach. The workflow in this paper was started by modeling the optimal fracture half-length using 2D/PKN model based on the slurry volume per stage. As a next step, the optimum pump schedule was created using 3D Pseudo hydraulic fracturing simulator. Furthermore, the sensitivity analysis was performed on HVFR-B at different pump rate, final proppant concentration, and proppant size to investigate the proppant transport and production performance. Finally, reservoir simulation tool was utilized to investigate the changing in fracture parameters and evaluating the Bakken oil production. The results showed that HVFRs with surfactant is the optimum hydraulic fracture fluids that showed better performance in proppant transport, which responded by high fracture capability to improve oil production. The findings can be applied and compared to other unconventional shale plays, such as Eagle Ford and Permian Basin.
Development and Application of Cyclic Stress Fracturing for Tight Oil Reservoir in Ordos Basin
Authors: Bai Xiaohu , Zhang Kuangsheng , Tang Meirong , Wang Chengwang , Wang Guanggao , Li Chuan , Zhang Tongwu , Xu Chuangchao , Wu Shunli , Wang Jianhui , Liu Shun , Wang Bei , Chen Qiang , Fu Yunlong
Published: November 2019

The Chang7 group in Ordos Basin usually shows low brittleness index, high differential principle stress and little natural fracture, which makes it difficult to generate complex fractures with traditional high rate hydraulic fracture practice. During a geomechanical test on core samples, complex fractures were unexpectedly found inside the test sample due to fatigue failure after cyclical stress loading below fracture gradient. Based on cyclic stress loading tests on cores and large-scale mockups, a cyclic stress fracturing technology was developed with specific operation procedure, downhole tools and optimized fracturing design parameters to generate complex fractures.

This technology injects high concentration slurry through tubing at low rate and slick-water through the annulus at various pump rate. The annulus injection rate changes constantly based on treating pressure and formation response, to achieve real-time control of bottomhole slurry concentration, in order to cyclically apply pressure on the formation rocks to induce fatigue failure, thus complex fractures are generated inside the low brittleness index Chang7 formation.

In the field trial of 24 wells, the wells fractured with cyclic stress technology showed increased fracture complexity, a 100% increase in stimulated reservoir volume in microseismic monitoring result and achieved 50% higher production than the wells treated by conventional fracturing technology.
Well Testing to Full Potential: Lessons Learned and Best Practices for High Rate Wells
Authors: Hollaender Florian , Shumakov Yakov , Karacali Ozgur , Theuveny Bertrand
Published: November 2019

Today many well test operations are performed in frontier environments targeting high potential oil and gas reservoirs or using high deliverability horizontal wells. Such highly productive wells cannot be dynamically evaluated to acquire representative reservoir data by small-scale flow tests.

High flow rate well tests are introducing a set of unique challenges that need to be addressed at the design stage of the test, each requiring an appropriate surface well test spread, DST string as well as job operation procedures and equipment planning. Currently, well tests aiming at achieving very high flow rates are often designed and executed on a case-by-case basis, and there are no practical recommendations available that would summarise the well testing experience in such environments and guide the operator through the process to efficiently plan the well test operations.

Well test operations are inherently challenging operations owing to the requirements for well control, accurate data acquisition, and the safe handling and disposal of produced fluids (hydrocarbons, completion brine, water, and solids), concerns are especially acute when considering high flow rates. Several past experiences have clearly shown limitations when trying to achieve high flow rates using conventional approaches and standard well test equipment.

Concerns range from equipment failure and operational issues to poor interpretability of acquired data from those tests, increasing the total costs of such well tests or in extreme cases leading to severe HSE incidents. Enhancements in well testing equipment such as new generation well test separators equipped with high-range Coriolis mass flow meters or new generation burners, combined with fit-for-purpose well testing techniques make it possible to overcome these challenges.

This paper will summarise the results and lessons learned from high flow rate well test operations performed around the globe on vertical and horizontal wells, in oil and gas reservoirs. The paper provides practical recommendations supported by a series of case studies from multiple oil and gas fields. The paper also describes a comprehensive list of challenges associated with high rate well test operations that can support successful operations design. Recipes for success are provided to ensure that safe operation can be performed in challenging environments.
Application of Hybrid ARIMA – Decision Tree Algorithm in Reservoir Pressure Surveillance
Authors: Mohammad Fuad Iqmal Irsyad , Rosli Luqman Hakim , Husni Husiyandi
Published: November 2019

Bottom hole pressures are valuable source of information for reservoir surveillance and management and are the heart of reservoir engineering. Real – time pressure measurements record pressure data at 5 second interval resulting in enormous accumulation of data. The size and volume of the accumulated data limit the capability of existing analysis software to load and interpret data. This paper presents an improved methodology for data quality checking and data optimization in determining reservoir pressure depletion via Autoregressive Integrated Moving Average (ARIMA) and Decision Tree Model.

Dataset was gathered from a representative reservoir from Malay Basin. The ARIMA algorithm presented was designed for quick and efficient data quality checking. The Decision Tree Model in other hand was utilized to select maximum buildup pressure for reservoir depletion point via well status parameters. The maximum pressures were selected from buildup up data when the decision tree conditions were met. Versus classical methods, the algorithm has obtained around 90% similarity. The resulting data were then can fully optimized for reserve reporting and forecasting study i.e. analysis and numerical simulation.

The paper also reports on the advantages in the application of ARIMA – Decision Tree Algorithm in pressure surveillance revealing few key advantages namely minimize the need of well intervention and optimized workflow for reservoir engineer to view, utilize, and detect reservoir depletion data. ARIMA – Decision Tree Algorithm is targeted to be installed and integrated in field historian for better overall data analysis and visualization. Results produced from the ARIMA – Decision Tree Algorithm which consist of reservoir pressure depletion data will then improve more advance analysis such as simulation and forecasting in terms of overall speed and accuracy.

As a conclusion, this paper presents the importance and application of incorporating Big Data Analytics Algorithm in reservoir management and reporting. Future work, deliverability calculations can be incorporated in the model to identify and rectify any abnormal reservoir behavior.
New Synthetic Acid Technology Used to Successfully Removing Scale Damage by Laboratory Custom-Designed Systems in HPHT Wells in Mexico´s Offshore
Authors: Diaz Perez Pablo Javier , Juarez Portillo Ernesto Adrian , Solano Gonzalez Francisco del , Jimenez Osorio Jose del
Published: November 2019

Stoichiometric evaluation performed in laboratory is presented comparing conventional hydrochloric acid and Synthetic Acid based stimulation systems in static and dynamic conditions to verify the speed and reaction performance applied in real tubing segments with severe Carbonate Scale at different times verifying efficiencies. With these tests, it was determined that Synthetic Acid system showed a higher dissolution efficiency, and it was applied in the stimulation of several wells located in Mexico´s Offshore, achieving successful results. Conventionally, carbonate scale complications in tubing production, downstream pipes, wellhead choke pipes, gas lift mandrels valves and surface pipes are corrected mostly with hydrochloric acid and occasionally with organic acids; in the quest of a solution to reduce the corrosion rate in pipes, increase in reaction efficiency and stability at critical pressure and temperature conditions, a synthetic acid system was developed which meets the established objectives compared to conventional systems. Tubing production pipes with carbonate scales was recovered during minor repair and cut into segments with equal dimensions, which were measured and weighed to quantify the stoichiometry of the two types of acid. The evaluation developed to dynamic and static conditions verified the impact that the turbulence has on the efficiency and speed of reaction in different observation times. Based on the results obtained from the laboratory tests, a stimulation treatment with Synthetic Acid was carried out in the oil producing well in the BKS formation, achieving immediate increases in their operating conditions (temperature, pressure in the downstream pipe, pressure in wellhead); subsequently the well maintained an incremental trend of its flow conditions over time. The use of synthetic acid to stimulate and remove the damage by precipitation of carbonate scale present in the formation water, allows it to do so without practically causing any corrosive damage, is highly efficient in dissolution and friendly to the environment.
Improvement in Rheological Features, Fluid Loss and Swelling Inhibition of Water-Based Drilling Mud by Using Surfactant-Modified Graphene
Authors: Rana Azeem , Saleh Tawfik A. , Arfaj Mohammad K.
Published: November 2019

The improved rheological properties of the drilling fluid are very critical for the oil well drilling operation. The present work reports the effect of sodium dodecyl sulfate modified graphene (SDS-Gr) on the rheological features, fluid loss and swelling inhibition mechanism of clay. The rheology and filtration test of drilling mud were conducted after being hot rolled for 16 h at 150oF and under 500 Psi pressure. The inhibition characteristics were evaluated by the dispersion test and shale inhibition durability test, where SDS-Gr modified drilling mud shows the highest recovery as compared to KCl and traditional drilling mud. The inhibition mechanism was investigated by various kind of techniques such as thermogravimetric analysis, scanning electron microscopy, and energy dispersive X-Ray spectroscopy. The outcomes revealed that the addition of SDS-Gr to the traditional drilling mud clearly affect the rheological properties and make it more suitable for the drilling. Moreover, SDS-Gr additive reduces fluid loss by 20% as compared to the mud without SDS-Gr. The Fourier transform infrared spectroscopic study also confirms the adsorption of SDS-Gr on clay. SDS carries the negatively charged functional group that help SDS-Gr to binds to the cations present on the clay surface and graphene plug the pores in the clay. The intercalation and adsorption of SDS-Gr on to the surface of clay hinder water molecules from invading the clay that helps in mitigation of swelling due to hydration. We report for the first time the SDS modified graphene (SDS-Gr) that successfully binds to the clay surface. In order to combine the features of SDS and graphene, the graphene surface is factionalized with SDS that modify the drilling mud rheology, control fluid loss and inhibit the clay swelling.
Integrating Digital Image Processing and Machine Learning for Estimating Rock Texture Characterization from Thin Section
Authors: Alkamil Ethar H. , Abbas Ahmed K. , Almubarak Haidar
Published: November 2019

A methodical rock texture characterization of core samples and cuttings can provide powerful information that can be used reliably and cost-effectively to optimize fracture stimulation designs by placing fracture stages based on rock characteristics and drill bit selection. This paper presents a method to quantify rock texture using a developed integrated digital image processing to the neural network segmentaion for the analysis of the core-plug thin section.

The standard routine uses the binarization process that converts the colored (RGB; Red Green Blue) core-plug thin section image into a set of binary images corresponding to different mineralogy content using the R, G, and B pixel values for thresholding. The idea is that the threshold values must accommodate all different colors that correlate to the rock texture and pore and help in creating a different mask (binary image) for each content type based on the threshold values used. The collection of the binary images for the different mineralogy will help in the rock texture interpretation. However, the neural network method used the data for multiple thin section images to learn based on the pattern of the color difference between pores and matrix. All results are validated with x-ray deflection (XRD).

The proposed integrated system results show that, the thin section used in this work from an oilfield in the southern of Iraq is mainly quartz with minor Kaolinite and other components, where the mineral color code and weight percentages are recorded and validated with XRD. The comparison between the proposed image processing approach, neural network, and the XRD analysis show that good agreement with an acceptable percentage of error. These variations can help in understanding the rock behavior, optimize fracture stimulation designs and selecting the appropriate drill bits for drilling applications. The variations can also help in smart completion designs.
Formation Damage Assessment and Waterflooding Incompatibility Study for Reduced Sulfate Injection Water
Authors: AlAamri Jamal , AlDahlan Mohammad , S Al-Yami Ibrahim , A. Al-Ghamdi Abdulaziz
Published: November 2019

Waterflooding has always been considered as a favorable technology to support reservoir pressure during production and enhance recovery. The main challenge that needs to be addressed is the increase in scale potential due to incompatibility of mixing two different waters of different physical and chemical properties. Calcium sulfate scaling can form as a result of the reaction of high calcium produced water with high sulfate injection water. Since there is no feasible method that can efficiently be used to reduce the high calcium content in the formation water, treating the injection water by adding scale inhibitor or lowering its sulfate content is of high interest. Reducing the sulfate content physically through RO membranes or chemically through ion exchange methods can be considered a solution.

In this study, different scenarios for using reduced sulfate simulated injection water (SIW) in addition to untreated SIW have been examined as options for waterflooding prior to field application recommendations. Three different concentrations of reduced sulfate SIW (100, 200 and 300 SO4− ppm) in addition to the untreated SIW with almost 4000 ppm of SO4− were used to study water-water reaction and water-rock interaction. The study scheme included static bottle testing for compatibility of the synthetic flooding water and SPW at different mixing ratios and coreflooding at different temperatures for the water-rock interaction.

Water-water interaction tests revealed that the reduced sulfate SIW was found to be compatible, and no sign of precipitatation was observed. Untreated SIW showed white precipitates of calcium sulfate when mixed with the high calcium synthetic simulated production water (SPW) at different ratios and temperature. Coreflooding formation damage assessment indicated a reduction in the commercial core plug permeability of less than 12%.

Reduced sulfate waterflooding can eliminate the risk of calcium sulfate scale formation damage and minimizing scaling mitigation and challenges requirements.
Non Stationary Next Generation Measurement While Drilling Tools
Authors: ElGizawy Mahmoud , Lowdon Ross , Breen Michael , Brovko Katerina , Edmunds Michael , Bulychenkov Konstantin , Mussa Shadi
Published: November 2019

The drilled wellbore is surveyed while drilling at stationary interval when drilling operation stops to connect a new stand. A next generation measurement while drilling MWD tool is developed to take a definitive survey while drilling either rotating or sliding. This has never been possible before where the entire drilling operation had to stop to take surveys. This paper is presenting results of first runs in the region and the gained benefits in drilling cost and time savings.

The current practice is to hold the drill string stationary to take the survey and allow the direction and inclination sensors to survey the wellbore. The survey time varies from 3 minutes and up to 5 minutes for some MWD tools. Any movement to the drill string will compromise the measurements quality where surveys will fail field acceptance criteria and become invalid. A new technology is developed to allow taking continuous measurements from three magnetometers and three accelerometers to determine accurate inclination and azimuth during drilling the wellbore without a need to stop.

The encouraging results from different runs in the region are presented. Potential time and cost savings are quantified. Surveys are taken every stand approximately every 100 ft. An average 500 minutes (8.6 hours) are needed to take wellbore surveys when drilling 10,000 ft well. For the first time, the new next generation measurement while drilling wellbore surveying tool will save this invisible lost time spent to take the stationary surveys. It improves the average rate of penetration, directional control, allows to complete the well in shorter time and saves on drilling costs. The advantages of continuously taking surveys while drilling is further presented and compared the traditional stationary surveys with respect to the improved well placement.

For the first time in the drilling industry it is possible to take definitive MWD surveys while drill string is rotating and drilling on bottom. The surveying results are very encouraging and show the high potential to maximize the drilling performance while save the drilling time and cost.
The Untold Story of Abu Dhabi's Recovery Based Strategy
Authors: Al Kindi Arwa , Al Tandi Ahmed , Abdou Medhat , Xu Siqing , Kumar Heer , Zivanov Drago , Loobari Sultan , Al Mazrouei Nadia
Published: November 2019

Every market intelligence on energy these days converges on a unanimous view that despite the push on developing alternative energies, fossil fuel will continue to play a pivotal role in world energy supply. The competition between fossil fuel and alternative energies is a new reality. To maintain a competitive edge, sustainability and favorable economic returns shape the UAE's approach to future oil developments.

UAE oil production is analyzed to reflect the critical importance of production contribution to the world and within the MENA region. Two published international field development cases are analyzed, focusing on the impact of aggressive approach on production sustainability, potential challenges and costs in developing the remaining bypassed oil. By using typical Abu Dhabi reservoir field data, various development scenarios are simulated demonstrating potential impact on production sustainability, ultimate recovery and economical value for the country.

Today National Oil Companies (NOC's) have an advantage as they own and control more than 90% of the total world oil and gas reserves. In contrast, the top six largest International Oil Companies (IOC's) combined control less than 5% of the total. Clearly, IOC's will face challenges in reserves replacement. Although there are different factors affecting reserves replacement rate, one of the key to enhanced economic reserves position for IOC's is field depletion strategy.

An ideal field depletion strategy would see production at lower depletion rates to ensure efficient reservoir drainage for maximizing recovery. An aggressive field depletion strategy can potentially generate faster monetary returns through higher production, but may create by- passed oil that would be difficult and costly to extract. An optimal field depletion strategy ensures sustainable development, maximizes ultimate recovery, and generates highest value return for the country and all stakeholders. A careful approach is required while deciding between these two different approaches, as the decision can have long lasting implications on corporates economic reserve position and global energy supply landscape. For example, a small improvement in ultimate recovery of existing reservoirs worldwide would add to and sustain affordable supplies, but a small reduction can potentially lead to supply shortages hindering world economic growth.

This paper presents the untold story of Abu Dhabi's Recovery Based Strategy. The aim is to perform a detailed analysis and comparison between two different development approaches, namely Aggressive Approach aiming to generate quick monetary value through high production (high depletion rates), and optimal / moderate field depletion strategy prioritizing sustainable development, and high ultimate recovery for all stakeholders.
Development of a Smart Slickwater with Highproppant-Carrying Capability for Shale Reservoirs
Authors: Ke Xu , Yongjun Lu , Xin Wang , Yang Shi , Minje Xu , Xiaohui Qiu
Published: November 2019

The early shale gas mining in North America mainly used linear adhesive fracturing fluid, and later, with the deepening of the research and the requirements of component control, the slippery water fracturing fluid system was gradually used. Because of its low viscosity, slippery water can easily communicate micro-cracks and layered seams at different scales, forming a complex volume of network cracks.

Hydraulic fracturing technology has been widely used in oil and gas industry to increase production since 1947. Linear and crosslinked guars are the most commonly used fracturing fluid system. Concerns over damage to conductivity caused by viscous fluids in unconventional reservoirs, the industry has developed an alternative fracturing fluid called slickwater, which consists mainly of water and the low concentration of linear polymer. Slickwater has the characteristic of poor sand carrying capacity, and it is necessary to develop a smart slickwater to improve sand carrying capacity.

The paper introduces a new smart slickwater with high proppant- carrying capability for shale reservoirs. The fluid system consists of linear self-assembled agent, which can improve the viscosity of slickwater at low concentration and maintain a high drag reduction rate. The advantage of the smart slickwater is that only one chemical additive is used, and when the concentration is 0.05%, the drag reduction rate can reach more than 75%, and when the concentration is 0.2%, the proppant ratio can reach 30%, replacing the linear and crosslinked guars.

Laboratory experiments were conducted using the smart slickwater to display excellent static and dynamic sand carrying capacity. The smart slickwater is used in Changqing Oilfield(China), compared with the traditional slickwater, the product is less expensive to use, less water for fracturing, less types and dosage of chemicals required, less equipment needed.

The new smart slickwater with high proppant- carrying capability can change the existing structure of fracturing fluid system.
The use of Geosteering to Achieve the Drilling Targets in Multilateral Fishbone Wells in Russkoye Field
Authors: Abaltusov Nikolay , Sukhanov Aleksandr , Zaripov Emil , Orlov Dmitriy , Enikeev Ruslan , Pitsyura Evgeniy
Published: November 2019

The purpose of the work performed is to show the possibility of using geosteering not only for achieving geological targets but also for supporting directional drilling operations in multilateral wells.

Drilling of multilateral "fishbone" design well in complex terrigenous section of Pokur suite in Russkoye field is reviewed as an example.

Three kick-off operations with the use of Rotary Steerable System were carried out in an open hole when drilling a horizontal section of the well under review. The well logs of the previous hole were used for optimal selection of the kick-off point.

To control the distance to the reservoir boundaries a 3 layers parameter inversion (based on azimuthal resistivity data) was used in addition to density and porosity sensors.

As a result of the operations performed, the optimal conditions for kicking off with the Rotary Steerable System, were identified within the geological structure of Russkoye field.

Geosteering in real time was successfully used not only for solving geological issues, but for directional drilling as well: optimal kick-off depths were selected for laterals, the trajectory was followed according to the plan; the problems related to bit deflections when the laterals exit the main productive formation were avoided.

The geological targets were delivered as well: the length of the hole in the target formation totaled 98.9%.
Intra- and Inter-Facies Variability of Multi-Physics Data in Carbonates. New Insights from Database of ALBION R&D Project
Authors: Danquigny Charles , Massonnat Gérard , Mermoud Cédric , Rolando Jean-Paul
Published: November 2019

In carbonates, the geological facies is a key driver for populating reservoir models with petrophysical properties. Conventionnal core analysis mainly contributes to establish relationships between facies, petrophysics and geophysics. However, populating gridblocks reservoir models with petrophysics requires parsimonious facies classifications and effective relationships at larger scales that field studies rarely investigate. Studying outcrop analogues helps filling the gap between lab measurements and effective upscaled properties of models, and considerably improves the modelling workflows.

The ALBION R&D project developed an innovative framework for multi-physics and multi-scales characterization of Barremian-Aptian carbonates from south-eastern France. These outcropping rudist-rich limestones constitute an analogue of Middle-East reservoirs. Petrophysical and geophysical properties were measured on plugs from cores and outcrops but also at larger scales thanks to original experiments on cores, in and between boreholes. Indeed the analogue includes several experimental areas, where hydraulic tests in sealed wells sections and tomographies between very close boreholes allowed investigating petrophysical and geophysical rock properties at intermediate decimetric to decametric scales. Thanks to the resulting database, this paper aims quantifying the variability of multi-physics data (e.g. porosity, permeability, and P-wave velocity) at different scales in regards of an updated and unified facies classification. The latter is only based on sedimentary origin and fabrics. Other available properties affecting petrophysics are used to cluster facies associations in sub-classes.

Consequently the facies classification does not allow discriminating the distributions of porosity, permeability, nor p-wave velocity. For the rudist facies, that is the most sampled, texture subclasses do not help this work. Reversely, the place of sampling, that is likely a proxy of diagenesis and age, cluster the petrophysical distributions. The results remind us that a proper facies definition should consider both sedimentary origin, fabrics, texture, diagenesis and tectonics. They also point out the relative importance of each characteristics in regards of the scale of interest and the difficulty to infer upscaled relationships between rock properties from CCAL because the representative elementary volume of carbonates is usually higher than the plug and even the core volumes.
Laboratory Study of Environmentally Friendly Drilling Fluid Additives to be used a Thinner in Water-Based Muds
Authors: Al-Hameedi Abo Taleb , Alkinani Husam H. , Dunn-Norman Shari , Al-Alwani Mustafa A. , Feliz Justin D. , Alshammari Abdullah F. , Albazzaz Hussien W. , Hamoud Zahra A. , Mutar Rusul A. , Al-Bazzaz Waleed H.
Published: November 2019

The use of conventional chemical additives to control drilling mud specifications causes serious health, safety, and environmental side effects. To mitigate these lasting hazards, an economic multifunctional bioenhancers should be exploited as additives in place of the traditional materials to achieve the desired drilling mud properties. Using a bioenhancer is not only safer for the environment, but it poses no risk to drilling personnel and is more cost-efficient than conventional methods.

In this work, two concentrations of is Palm Tree Leave Powder (PTLP) were added to the base mud and drilling fluid properties were measured. The pH test demonstrated PTLP's ability to minimize alkalinity. At 1.5% (11 gm) PTLP, the pH was decreased by 21%, while 3% (22 gm) PTLP showed a reduction of 28%. A reduction in seepage loss (cc/30min) of 26% and 32% was also observed, respectively, when comparing it to the reference fluid. Simultaneous improvement of the mud cake was seen over the reference fluid, signifying PTLP could also substitute fluid loss control agents. The plastic viscosity (PV) of the reference fluid was insignificantly affected by the introduction 1.5% (11gm) PTLP. However, when the concentration of PTLP was increased to 3% (22 gm) a tangible increase in PV was seen due to the inefficient grinding of the palm tree leaves (PTL) and irregular dispersal of particle sizes. To mitigate this, a more effective form of grinding for PTL is needed as well as a sieve analysis to ensure equal distribution of particle sizes. The second component of viscosity, yield point (YP), was drastically reduced by 59% at both 1.5% (11 gm) and 3% (22 gm) as compared to the reference fluid. Additionally, initial and final gel strengths were significantly reduced at both concentrations. These results are an indicator that PTLP can be a viable option as a thinning material for water-based mud.

Considering the previously stated results, PTLP can be a feasible replacement or at least supportive material for conventional pH reducers, filtration loss control agents, and viscosity thinners. This biodegradable drilling mud additive shows great potential and is a practical option to replace or at least support toxic chemicals traditionally used such as lignosulphonate, chrome-lignite, and Resinex. This work outlines a practical guide for reducing drilling fluid costs as well as the impact on drilling personnel and the environment.
Incidents Investigations and Learning Approach in Oil & Gas Industry
Authors: Al-Qubaisi Salama Saeed
Published: November 2019

Incident investigation makes an important contribution to reduce risk by implementing recommendations and Lessons Learned from an investigation. Lessons Learned from an Investigation is an instrument to prevent future reoccurrence and it requires effective implementation. Nevertheless, the implementations of the lessons learned from the incidents require a systematic approach and management methodologies, which include Processes, Procedures and a Robust System, that ensure lessons are captured, validated, implemented and utilized in future activities and projects. In most organizations, lessons are captured only within one segment that lacks an effective mechanism for sharing and implementing Lessons Learned. Therefore, omissions are often repeated from one activity or project to the next. This paper discussed the effective implementation of the Lessons Learned through Pan Company Process and System that positively adds value to an oil and gas organization. The Developed framework with "Common Database System" in ERP platform to facilitate Lessons Learned from various activities is embedded into Common Processes and Procedures. Therefore lessons are pro-actively routed to those who need to see them and take appropriate action. The Common System shall provide the aspects required to identify, assess and take corrective action on any issue and to communicate results for effective implementation across the company. This Process cuts across functional boundaries and allows an organization to learn from both its blunders and triumphs. The Lesson Learned System will support organization in learning efficiently from experiences that will reduce operational risk, increase efficiency, and improve operational effectiveness. In addition, it presents opportunities to save time, money and to add value to company standards. The gains from the idea will usually materialize over the longer term. This is encouraging Knowledge Management (KM) sustainability by learning, exchanging and implementing valuable lessons learned across all aspects of Company business activities. Such lessons shall be referred to prior starting a new activity or project. The paper proposes a novel method to manage Lessons learned from Incidents. An efficient Lessons Learned process could inhibit organization from rerunning their errors and allow organization to repeat their accomplishments. It should be an instrumental part of any organization's overall continuous improvement process.
Methodology for Recoil Analysis of Emergency Disconnection Drilling Riser in a Deepwater Environment
Authors: Wang Yanbin , Gao Deli , Wang Jinduo
Published: November 2019

In deepwater drilling, it is inevitable to disconnect the riser from the Low Marine Riser Package (LMRP) with the blowout preventer (BOP) under some extreme operating conditions. Since the riser is in tensile state under normal working conditions, elastic potential energy is stored in the riser. So, the riser will move upward like a spring under the combined action of the elastic potential energy and the frictional resistance generated by the discharge of drilling mud in riser, which is called recoil response. Recoil analysis of drilling riser is of great significance to the safety of deepwater drilling, from which the recoil response, main controlling factors and corresponding solutions can be defined.

In this paper, the mechanical model and governing equations are established based on the mass-spring-damping system with two degrees of freedom. In this model, the frictional resistance on the riser inner wall when the drilling fluid is discharged, and the elastic potential energy stored in the riser are taken into account. In addition, the direct acting tensioner (DAT), which is simplified as sinusoidal motion and spring model, is selected as the top boundary condition of the disconnected riser. The tension force and spring stiffness is calculated based on the configuration and working principle of the DAT. Finally, the time-history displacement of the LMRP after disconnected from the BOP is obtained. On this basis, the parameter sensitivity analysis is presented.

Analysis results show that with the increase of water depth and the amplitude of the DAT, the possibility of collision between them rises. For a determined riser system, there is an optimal heave motion frequency for the DAT to implement riser emergency disconnection. Corresponding measures should be taken to prevent the spring stiffness of the DAT from decreasing. Besides, the riser size has a comprehensive effect on the riser recoil response. This paper can provide reference for the research of riser emergency disconnection.
Integrated Approach for Smart Brownfield Concept - Application Model for Production Optimization Technologies
Authors: Windisch Christian , Doppelreiter David
Published: November 2019

This paper presents a novel approach for oilfield digitalization from an operator perspective in view of big data and industry 4.0 topics. The objective is to organize a smart technology change to state-of-the-art conditions in mature brownfields under the circumstances of a low oil prize scenario, minor hydrocarbon production rates, high water cuts and the availability of a certain percentage of a well’s turnover for digitalization and monitoring purpose, as demand from the company’s management.

The core of the smart brownfield concept is the formation of a team of multidisciplinary professionals, working on projects outside the day-to-day business, with the aim of introducing and developing state-of-the-art technology solutions in order to optimize production in mature brownfields. The project team consists of three main pillars to cover organizational, commercial and technical key aspects. The relinquishment of internal IT services, as well as a focus on individual skills of each team member are primarily responsible for the successful implementation of the defined objectives.

Combining more than 80 years of operational experience in brownfield development with new state-of-the-art technology approaches, forms the basis for effective oilfield digitalization. The multidisciplinary project team conducts the elaboration of a holistic approach covering all relevant operational disciplines, under the aspects of production improvement, cost savings and health and safety compliance. Data generation is established by using purpose built devices, and by equipping wells with commercially available sensors. Data transmission is accomplished with a new approach in terms of LPWAN (Low Power Wide Area Network). Field operator are equipped with smart watches for data communication purpose during on-site field inspection. An internal developed software platform using the advantage of machine learning and smart computational approaches forms the base system for innovative analysis of automatically transferred field data. The project team programs integrated software applications for smart data visualization based on long-term expert knowledge in field operations. The so created oilfield digitalization concept serves as platform for field development and decision-making purpose for engineering and management level.

A big advantage of the created concept is, that the workflow can be applied to any oilfields and facilities around the globe for different well types (SRP, PCP, ESP) and customized according to required settings. The novel concept forms a holistic approach in a retrofit design, to combine the old analog and the modern digital world for a smart digitalization of brownfields in the E&P business.
Towards a Zero-Skin Well Completion with Non-Damaging Non-Corrosive Enzymatic Wellbore Cleanup Fluids
Authors: Ghosh Bisweswar , AlCheikh Ismail , Ghosh Debayan , Osisanya Samuel
Published: November 2019

The objectives of this study were; (1) selection of size distribution of bridging particles of polymer-based drill-in fluid based on the actual reservoir porosity distribution in order to minimize the internal filtration damage, and (2) to develop a non-corrosive wellbore cleanup fluid comprising of a specially designed bio-enzyme and in-situ organic acid precursors to remove the external filter cakes and bring the skin close to zero prior to well completion. Drill-in-fluids were formulated and developed based on Ideal Packing Theory (IPT). The calcite particle size simulation was conducted using a particle size simulator based on IPT using FMI log information from a carbonate reservoir. Xanthan-starch specific bio-enzymes were screened and optimized to achieve complete dissolution of the polymers present in the mud-cakes. Acid precursors were formulated and developed to dissolve the calcite particles and at the same time keeping the corrosion level below the maximum acceptable limit. Compatibility tests between the acid precursors and the bio-enzymes were performed. The final cleanup formulation was subjected to corrosion studies at dynamic conditions. The entire development was verified at reservoir conditions through core flooding experiments.

The formulated fluid was tested successfully against ceramic disks and carbonate core plugs by performing core-flood tests. The polymer based drill-in-fluid resulted in a very low permeability filter cake (<0.1 md), preventing internal filtrate damage significantly. Deposition of a very low permeability filter cake was achieved on carbonate core plugs which results in reduced damaging invasion. Several ester hydrolysis reaction kinetics were studied and finally one combination was chosen as the suitable acid precursor, because of their ability to generate required concentration of acid within three hours of hydrolysis at downhole condition. The best acid precursor satisfied the requirements by generating 3% of acid needed after 3 hours and maintained low acid concentrations for 12 hrs. The corrosion rates were found to be significantly below the industry limits and use of acid corrosion inhibitor is not necessary. Return-permeability of mud damaged carbonate core plugs was as high as 96% after exposing to clean-up solution.

A new drill-in fluid has been developed and its filter-cake deposition was completely cleaned up with enzyme-acid precursor combination. Normally wellbore cleanup fluids are highly acidic and need corrosion inhibitor. The new formulation was effective in minimizing corrosion of downhole tools without the use of corrosion inhibitors.
An Innovation Retrofit Solution Converting ICD to AICD Completion Leading to Enhanced Oil Recovery and Inventory Optimization
Authors: Khunmek Thanudcha , Abu-Jafar Feras , Chigbo Ikenna , Laoroongroj Ajana , Mohd Ismail Ismarullizam , Parrott Keith
Published: November 2019

This paper describes a pilot program for the application of an Autonomous Inflow Control Device (AICD) by retrofitting an existing ICD completion for reservoir optimization. New drill horizontal wells were required to be completed with AICD's to enhance recovery with existing ICD completion materials in inventory desired to be used. The workflow for establishing the decision change from ICD to AICD completion and the completion design process change is discussed.

The well program was selected to demonstrate the effectiveness of AICDs in the Jasmine asset, a current field development in Thailand. ICD screens had previously been purchased for a different application but were unused. To reduce overall project cost and asset inventory, a method of utilization the existing ICD screens was strongly desired. An evaluation was done, followed by design and development of a manufacturing process to retrofit the ICD screens with larger sized AICD housing. Furthermore, overall completion design was implemented to ensure a smooth deployment and optimized production benefit.

Multiple joints of existing ICD screens were successfully retrofitted with AICD technology locally within the region. The operator was able to reduce current inventory book levels by 20% that resulted in a direct cost saving of 40% comparing to new AICD screen cost. The field deployment of the retrofit completion was a success without any operational issues.

Despite the improved productivity and uplift in reserve recovery associated with horizontal wells, reservoir heterogeneity can cause uneven production and early water and gas breakthrough from portions of the wellbore. The AICD delivers a variable flow restriction in response to the properties (viscosity) of the fluid with water or gas flow restricted. With multiple segmentation along the horizontal section in this application, excessive production of unwanted gas and water have been limited. Installed in late 2017 and another application in 2018, production from the wells have exceeded expectation, with an uplift in recovery.