bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of Neural Networks and Wellbore Stability, a Modern Approach to Recognize Drilling Problems Through Computer Vision
Authors: Rocha Vargas Luis Alejandro , Izurieta Carlos Andres 
Published: December 2021

Abstract
Cavings are a valuable source of information when drilling operations are being performed, and multiple parameters can contribute to producing cavings which indicate that failure has occurred or is about to occur downhole. This study will describe a project which is an integrated study of Machine Learning, Computer Vision, Geology, and Photography so that the recognition of cavings in the shaker is possible and how to link the cavings morphology with causal mechanisms related to wellbore instability problems. This study aims to develop a model which can extract caving features such as Shape, Edge Definition, Color, and Size.
One of the core aspects of this study was to develop a structured image database of cavings from the Norwegian Continental Shelf which contains important feature information and the application of different algorithms used for automation enabled several opportunities to analyze and identify causal mechanism related to wellbore instability problems in real-time. As a result of that, the drilling operations would experience an improvement in terms of a faster decision-making process to solve operative problems related to wellbore stability which will lead to optimization not only in time and resources but also in safer drilling operations.
Different algorithms and artificial intelligence tools were used to investigate the best approach to correctly detect and derive meaningful information about the shape, color size and edge from cavings like supervised learning, unsupervised learning, neural networks and computer vision. A key part of this study was image augmentation which plays a significant role for the detection of the cavings and their features. Multiple data sets can be created, and by using data augmentation, this will enable recognition of more complex patterns that will have on-rig applicability. Also, this new approach can deliver multiple outcomes besides failure mechanism identification such as volume of rocks being drilled, transport of cutting, type of formation being drilled.
Comprehensive Analysis of Production Loggings in Fuling Shale Gas Play in China
Authors: Liu Yaowen , Pang Wei , Shen Jincai , Mi Ying 
Published: December 2021

Abstract
Fuling shale gas field is one of the most successful shale gas play in China. Production logging is one of the vital technologies to evaluate the shale gas contribution in different stages and different clusters. Production logging has been conducted in over 40 wells and most of the operations are successful and good results have been observed. Some previous studies have unveiled one or several wells production logging results in Fuling shale gas play. But production logging results show huge difference between different wells. In order to get better understanding of the results, a comprehensive overview is carried out. The effect of lithology layers, TOC (total organic content), porosity, brittle mineral content, well trajectory is analyzed.
Results show that the production logging result is consistent with the geology understanding, and fractures in the favorable layers make more gas contribution. Rate contribution shows positive correlation with TOC, the higher the TOC, the greater the rate contribution per stage. For wells with higher TOC, the rate contribution difference per stage is relatively smaller, but for wells with lower TOC, it shows huge rate contribution variation, fracture stages with TOC lower than 2% contribute very little, and there exist one or several dominant fractures which contributes most gas rate. Porosity and brittle minerals also show positive effect on rate contribution. The gas rate contribution per fracture stage increases with the increase of porosity and brittle minerals. The gas contribution of the front half lateral and that of latter half lateral are relatively close for the "upward" or horizontal wells. However, for the "downward" wells, the latter half lateral contribute much more gas than the front half lateral. It is believed that the liquid loading in the toe parts reduced the gas contribution in the front half lateral.
The overview research is important to get a compressive understanding of production logging and different fractures’ contribution in shale gas production. It is also useful to guide the design of horizontal laterals and fractures scenarios design.
Study on the Oil Displacement Effect and Application of Soft Microgel Flooding Technology
Authors: Zhang Jian , Sun Zhe , Wang Xiujun , Kang Xiaodong 
Published: December 2021

Abstract
Due to the reservoir heterogeneity, there is still a lot of remaining oil that cannot be displaced by water flooding. Therefore, taking the whole injection-production flow field as the research object, the dominant channel is divided into macro and micro channel. Then the corresponding oil displacement system is adopted to realize the continuous flow diversion and effective expansion of swept volume. For micro channels, the soft microgel particle dispersion can be used. It is a novel flooding system developed in recent years. Due to its excellent performance and advanced mechanism, the oil recovery rate can be greatly improved.
Soft microgel particle dispersion consists of microgel particles and its carrier fluid. After coming into porous media, its unique phenomenon of particle phase separation appears, which leads to the properties of "plugging large pore and leave the small one open", and the deformation and migration characteristic in the poros media. Therefore, particle phase separation of soft microgel particle dispersion is studied by using the microfluidic technology and numerical simulation. On this basis, by adopting the NMR and 3D Printing technology, the research on its oil displacement mechanism is further carried out. Furthermore, the typical field application cases are analyzed.
Results show that, soft microgel particles have good performance and transport ability in porous media. According to the core displacement experiment, this paper presents the matching coefficient between microgels and pore throat under effective plugging modes. Also, the particle phase separation happens when injecting microgels into the core, which makes the particles enter the large pore in the high permeability layer and fluid enters into small pore. Therefore, working in cooperation, this causes no damage to the low permeability layer. On this basis, theoretically guided by biofluid mechanics, the mathematical model of soft microgel particle is established to simulate its concentration distribution, which obtained the quantitative research results. Furthermore, the micro displacement experiment shows that, microgels has unique deformation and migration characteristic in the poros media, which can greatly expand swept volume. The macro displacement experiment shows that, microgels have good oil displacement performance. Finally, the soft microgel particle dispersion flooding technology has been applied in different oilfields since 2007. Results show that these field trials all obtain great oil increasing effect, with the input-output ratio range of 2.33-14.37. And two field application examples are further introduced.
Through interdisciplinary innovative research methods, the oil displacement effect and field application of soft microgel particle dispersion is researched, which proves its progressiveness and superiority. The research results play an important role in promoting the application of this technology.
Near-Borehole Imaging Using Full-Waveform Sonic Data
Authors: Alqatari Hala , Tonellot Thierry-Laurent , Mubarak Mohammed 
Published: December 2021

Abstract
This work presents a full waveform sonic (FWS) dataset processing to generate high-resolution images of the near-borehole area. The dataset was acquired in a nearly horizontal well over a distance of 5400 feet. Multiple formation boundaries can be identified on the final image and tracked at up to 200 feet deep, along the wellbore's trajectory.
We first present a new preprocessing sequence to prepare the sonic data for imaging. This sequence leverages denoising algorithms used in conventional surface seismic data processing to remove unwanted components of the recorded data that could harm the imaging results. We then apply a reverse time migration algorithm to the data at different processing stages to assess the impact of the main processing steps on the final image.
Application of a Novel Ecofriendly Okra Powder as Fluid Loss Controller in Water Based Drilling Fluids
Authors: Murtaza Mobeen , Tariq Zeeshan , Zhou Xianmin , Al Sheri Dhafer , Mahmoud Muhammad , Kamal Shahzad 
Published: December 2021

Abstract
Saudi Arabian based companies are spending many millions of dollars a year on import of drilling mud additives to meet the drilling industry demand. To cut the imported materials, locally available materials are preferable. Out of many drilling fluid additives, a single locally available additive such as fluid loss can save millions of dollars a year. The cost and locally available raw material justify the development of drilling fluid additives in the Kingdom of Saudi Arabia. In other aspect, local development provides many benefits to the Kingdom including industrial growth, technology ownership and new job opportunities.
Okra (Hibiscus esculents) is widely used as a thickener and viscosifier in medical and food industries due to its low cost, availability, longer shelf life, and high thermal tolerance. In addition to that, it is environment friendly and available in abundance locally in Kingdom of Saudi Arabia. The composition of Okra powder was diagnosed by X-ray fluorescence (XRF) and Fourier-transform infrared spectroscopy (FTIR). The thermal stability of Okra was tested using thermal gravimetric analysis (TGA). The Okra powder was mixed in various concentrations such as (1, 2 and 3) grams in 350ml of water based drilling fluid (WBDF). The performance of Okra contained drilling fluids was compared with starch-based drilling fluid. The addition of Okra reduced fluid loss in different proportions at different concentrations. For instance, drilling fluid with 3g Okra concentration had 42% lower fluid loss as compared to the base fluid. The cake thickness was reduced upon the addition of Okra. The low fluid loss and thin filter cake make Okra a useful solution as a fluid loss controller in WBDFs. The addition of Okra powder also increased the viscosity and gel strength of the WBDFs. TGA analysis of Okra powder showed that it has strong thermal stability as compared to starch. Overall, the experimental results suggest that Okra mixed drilling fluids can be used as an alternate solution to starch mixed drilling fluids.
Numerical Investigation of the Influence of the Drill String Vibration Cyclic Loads on the Time Dependent Wellbore Stability Analysis
Authors: Kamgue Lenwoue Arnaud Regis , Deng Jingen , Feng Yongcun , Songwe Selabi Naomie Beolle 
Published: December 2021

Abstract
Wellbore instability is one of the most important causes of Non-Productive Time causing billions of dollars of losses every year in the petroleum industry. During the drilling operations, the drilling mud is generally utilized to maintain the wellbore stability. However, the drilling mud is subjected to fluctuations caused by several processes such as the drill string vibration cyclic loads which can result into wellbore instability.
In this paper, a nonlinear finite element software ABAQUS is utilized as the numerical simulator to evaluate the time dependent pore pressure and stress distribution around the wellbore after integration of drill string vibration cyclic loads. A MATLAB program is then developed to investigate the wellbore stability by computation of the time dependent wellbore collapse pressure and fracture pressure.
The numerical results showed that the safe mud window which was initially constant became narrower with the time after integration of vibration cyclic load. The collapse pressure without vibration cyclic load increased by 14.33 % at the final simulation time while the fracture pressure decreased by 13.80 %. Interestingly, the safe mud windows widened with the increase of the normalized wellbore radius as the wellbore fracture pressure increased and the collapse pressure decreased.
This study provides an insight into the coupling of the wellbore stability and the continuous cyclic loads generated by drill string vibrations which is an aspect that has been rarely discussed in the literature.
Successful Barrier Enhancement Application of Epoxy Based Resin for Multiple Casing to Casing Annuli Having Tight Injectivity - Case Study from Saudi Arabian Peninsula
Authors: Shamsan Abdulmalek , De la Cruz Alejandro , Jimenez Walmy 
Published: December 2021

Abstract
This study describes the approach used for enhancing the well integrity that was compromised with gas flow through a casing-casing annulus (CCA). Extremely tight injectivity at a CCA demands a solid free solution which not only can be injected but also resist high differential pressures to provide a long-term barrier in CCA. In this paper a successful leak remediation using an epoxy resin system helped the operator save a well and restart its production. Several pressure tests were conducted for identifying an extremely tight casing leak which was causing formation gas travelling to surface through the annulus. This issue required the customer to look for an efficient remedial solution to seal off the gas leakage and regain productivity. Due to the extremely low injectivity, a conventional cement squeeze or any solid laden particle-based squeeze approach was prone to fail. Alternatively, a tailored solid free epoxy resin system was placed in the annulus using an unconventional placement technique resulted in barrier enhancement and helped the operator place the well back into production. For a mature well flowing through 7 × 9 5/8‑in. and 9 5/8 × 13 3/8‑in., a tailored epoxy-based resin system formulation was placed in the well bore with modified surface operations procedures which helped in eliminating current annular pressure to regain well integrity and production. Remedial operations were performed from the surface by squeezing to seal off the gas coming from the annulus. A Tailored design derived from rigorous lab testing and perfect field execution resulted in CCA pressure remediation in a single attempt of the treatment injection, proving that the concept of using a solids-free resin to enhance existing deteriorated barriers is a reliable method. This epoxy resin system helped the operator to regain the well integrity and production in the shortest time without expensive well intervention operations. Epoxy resin based systems have been identified as a novel solution to remediate barrier integrity for well construction and workover operations, hence such case histories with enhanced operations procedures are helpful in increasing awareness of the benefits that can be attained in challenging high-pressure, low-injectivity environments, and can improve well economics.
Apparatus and Method for Strain Energy Based Resiliency Measurement of Loss Control Materials
Authors: Amanullah Md , Alouhali Raed , AlArfaj Mohammed 
Published: December 2021

Abstract
Loss of circulation is one of the greatest challenges that are frequently encountered while drilling. Various types of LCM products are used by the industry to combat loss of circulation. Characterization of these LCM products is very important to select the most suitable products to improve the success rate of LCM treatment jobs. This paper describes the theoretical basis of the application of strain energy along with the development of a strain energy-based mathematical model to create a dedicated software driven novel method and test apparatus for quick and reliable measurement of the coefficient of resiliency of various LCM products to improve the likelihood and probability of success rate of LCM treatment jobs. The simple but reliable method and apparatus provide a fit-for-purpose solution for additional characterization of LCM products.
The design and construction of the test device and the development of the method considered the most critical technical factors that have high impact on data reliability, data accuracy, repeatability and data sensitivity. The components of the test device were selected based on technical, economical, portability and ease of operation using a dedicated software driven method and data acquisition system.
Experimental results generated by loading and unloading a particular mass of a LCM product under a constant displacement rate of the loading foot of the test apparatus demonstrated the suitability of the method and the apparatus in determining the coefficient of resiliency of LCM products. Based on the area below the loading curve i.e. the strain energy absorbed during the loading cycle and the area below the unloading curve i.e. the strain energy desorbed during the unloading cycle, the data acquisition software automatically calculates the coefficient of resiliency of the LCM products.
The resilient characteristic of LCM products is one of the critical factors that is very important for high performance pill or slurry design to enhance the seal/plug stability. Hence, the newly developed method and apparatus will play a positive role to improve the probability and the likelihood of creating a stable and lasting seal/plug in the loss zones. As loss control materials with good resilient properties are highly adaptable in changing stress and pressure conditions, this method can provide appropriate guidelines to mud chemists, mud engineers and mud consultants in designing high performance LCM blends or slurries to combat moderate and severe loss of circulation.
The Importance of Subsurface Characterization and Monitoring During Development and Operation of Underground Gas Storage Facilities
Authors: Guises Romain , Auger Emmanuel , Bordoloi Sanjeev , Ofi Ayodele , Cranfield Colin , Freitag Hans-Christian 
Published: December 2021

Abstract
Natural gas consumption is expected to grow significantly in coming decades in response to cleaner energy initiatives. Underground gas storage (UGS) will be key to addressing supply and demand dynamics for this transition to be successful. This technical paper will demonstrate the importance of an integrated subsurface characterization and monitoring approach not only for the construction of UGS, but also to guarantee safe and efficient operation over many decades.
Key to long-term success of UGS is maximizing working capacity with respect to volume and pressure and maintaining well injection and withdrawal capabilities. Initial assessment steps involve determination of maximum storage capacity and an estimation of required cushion gas volumes. In similar manner to conventional field evaluation, we perform an integrated geological, geophysical, petrophysical and geomechanical characterization of the subsurface. However, for UGS facilities, the impact of cyclic variations of reservoir pressures on subsurface behavior and cap rock integrity also needs to be evaluated to determine safe operating limits at every point in time during the life of the UGS project.
The holistic approach described above allows the operator to optimize the number of wells, well placement, completion design, etc. to ensure long-term safe and efficient operations. Furthermore, close integration of subsurface understanding with optimization of surface facilities, such as the compression system, is another critical component to ensure optimum UGS performance and deliverability. Moreover, another important task of the final phase of UGS facilities design involves enablement of sustainable operation through an asset integrity management plan. This phase is articulated around reservoir surveillance plans that monitor pressure, rock deformation and seismicity, in addition to regular wellbore inspection. Through close operations monitoring and the utilization of advanced data analytics, observations are compared to existing models for validation and operation optimization. Importantly we show that adapted monitoring programs provide critical long-term insight regarding the field response during successive cycles, leading to significant improvement in working gas capacity.
A key consideration of this integrated UGS development strategy is based on the seamless integration of subsurface characterization, wellbore construction and well completions to ensure technical and commercial flexibility. The approach also emphasizes the integration with surface facilities design to ensure a true "Storage to Consumer" view for effective de-bottlenecking. Coupled with integrated subsurface integrity monitoring, this ensures a faster, cost efficient and safe response to the construction and operation of UGS facilities.
A Comprehensive Model Integrating the Stress Sensitivity for Pressure Transient Behavior Study on the Two-Zone System for Offshore Loose Sandstone Reservoirs
Authors: Cao Chong , Cheng Linsong , Zhang Xiangyang , Jia Pin , Lu Wenpei 
Published: December 2021

Abstract
Permeability changes in the weakly consolidated sandstone formation, caused by sand migration, has a serious impact on the interpretation of well testing and production prediction. In this article, a two-zone comprehensive model is presented to describe the changes in permeability by integrating the produced sand, stress sensitivity characteristics. In this model, inner zone is modeled as a higher permeability radial reservoir because of the sand migration, while the outer zone is considered as a lower permeability reservoir. Besides, non-Newtonian fluid flow characteristics are considered as threshold pressure gradient in this paper. As a result, this bi-zone comprehensive model is built. The analytical solution to this composite model can be obtained using Laplace transformation, orthogonal transformation, and then the bottomhole pressure in real space can be solved by Stehfest and perturbation inversion techniques. Based on the oilfield cases validated in the oilfield data from the produced sand horizontal well, the flow regimes analysis shows seven flow regimes can be divided in this bi-zone model considering stress sensitive. In addition, the proposed new model is validated by the compassion results of traditional method without the complex factors. Besides, the effect related parameters of stress sensitivity coefficient, skin factor, permeability ratio and sanding radius on the typical curves of well-testing are analyzed. This work introduces two-zone composite model to reflect the variations of permeability caused by the produced sand in the unconsolidated sandstone formation, which can produce great influence on pressure transient behavior. Besides, this paper can also provide a more accurate reference for reservoir engineers in well test interpretation of loose sandstone reservoirs.