bluuebunny/crossref_metadata_2025_split huggingface dataset:
Underbalanced Drilling, Logging & Completion Operation Leads to 4.5 Times Production Improvement as Compared to Offset Wells
Authors: UlHaque Muhammad Moawwaz , Saboor Abdul , Bouarfetine Djillali , Hammoudi Abdelmalek , Serhane Hassen 
Published: January 2020

Underbalanced drilling technology is widely used to reduce formation damage in the reservoir section and improve productivity with the resulting ancillary benefit of improved drilling performance. It involves drilling with a fluid whose equivalent hydrostatic pressure is lower than that of the formation being drilled. As a consequence of this lower hydrostatic pressure there is a continuous flow of hydrocarbons to surface which is handled by separation equipment and exported thru pipelines where they exist or burned at the flare if no transportation infrastructure is located near rig-site.
The most prevalent method of implementing UBD drilling operations in Hassi Messaoud field for Sonatrach, involve using the concentric casing method to inject Nitrogen. Doing so ensures that downhole motor and MWD tools performance is not adversely affected by the presence of nitrogen gas lowering their performance. Concentric casing injection insures that the open hole section is only exposed to native crude further reducing the potential for reservoir formation damage. This is achieved by injecting single phase crude down the drill string and nitrogen is injected thru the well head between the tie back liner and previously set casing.
The introduction of nitrogen in the main annulus is achieved by means of concentric casing injection ports this has the desired effect of lightening the hydrostatic pressure of the drilling fluid to lower than the reservoir pressure thereby leading to inflow of hydrocarbons while drilling ensues. The excess produced hydrocarbon is exported to nearby production facility. Drilling underbalance drastically reduced formation damage when compared to offset wells which was evident from production testing results. The well was drilled to TD, logged and completed underbalance as well, leading to crude production rate that is 4.5 times greater than average production rate of the nearest four offset wells in same production area which were drilled conventionally.
Additionally, by producing the crude during underbalanced drilling operations prior to being handed over to production department, the well was able to recover 40% drilling cost which substantially offset the cost of UBD operations. This paper examines how the implementation of underbalance techniques resulted in successfully drilling, logging and completing the well in underbalance conditions resulting in significant productivity gains for the operator.
Sand Production Tendency in the World's Largest Clastic Oil Reservoir - An Evolving Experience
Authors: Al Zankawi Omran , Al Ghareeb Aisha , Singh Hemant , Imtiaz Saad , Khaksar Abbas , Perumalla Satya 
Published: January 2020

The mature Greater Burgan field has the largest clastic oil reservoir in the world producing from multiple units for more than 70 years. Wara and Burgan are the two main sandstone reservoirs in the field with several sub-units of varying mineralogical and mechanical properties. Continuous oil production from some low strength reservoir units has resulted in pressure depletion and the associated water encroachment has led to the initiation of sand production in few wells. This paper presents an approach to analyze rock mechanics, reservoir and production data to predict the sanding tendency in a heterogeneous rock of the world's largest clastic oil reservoir.
Analytical poro-elastic geomechanical sanding evaluation approach was used to study rock failure and sand production. A number of wells (both with sand production and without sand production) were selected for geomechanical analysis based on the data availability and their respective location across the field. Various types of rock mechanical tests were performed with stringent quality control criteria to determine the mechanical characteristics of the rocks. Field calibrated geomechanical model along with reservoir and production data were used to build a calibrated sanding model for the Wara reservoir. The sanding model was then utilized to create sanding evaluation logs; perforation optimization and safe operating envelop plots for existing and future wells.
As per the calibrated geomechanical model, the reservoir units comprise intervals of variable rock strengths. The sanding model calibrated from offset wells suggested that drawdown and rock strength are the most sensitive parameters in failing the rock and sand production. The wells with and without sanding had mixed response to water breakthrough and there does not seem to be any obvious pattern of sanding observed with respect to the onset of water production in the wells. It was also noticed that few offset wells did not exhibit sand production despite strength and stress conditions in these wells were favorable for early sand production. Potential explanation was found for those cases. These models helped to identify selective intervals to optimize sand-free production with limited drawdowns. However, for wells with very high drawdowns (installed with artificial lift pumps and 1000 psi drawdown pressure), none of the prolific sand interval could be stable and downhole sand control measures may be required.
The combination of measured and modelled parameters have helped to understand the sanding tendency and behaviors of a highly heterogeneous reservoir. This analysis has produced guidelines on the best and worst well trajectories and optimum perforation orientations to mitigate well-life sanding risks with a rock strength sensitivity. Furthermore, data priorities have been identified in order to come up with holistic sand management strategy.
Microscopic Scale Experimental Investigation into Fracturing Fluid Uptake Pathways for Tight Carbonate Source Rocks
Authors: Liang Feng , Zhang Jilin , Liu Hui-Hai , Zhang Shawn 
Published: January 2020

Hydraulic fracturing has been widely used in stimulating unconventional reservoirs, including tight carbonate formations, to improve oil and gas production. The stimulation process requires massive volumes of fracturing fluid to crack the formation; however, only a small percentage of the fluid is recovered during the fluid flow back process. Where the remaining fluids reside in the formation is still not clear. This work strives to use microscale radiographic imaging to study the fluid uptake pathways.
The spontaneous imbibition of fracturing fluid into organic-rich carbonate source rock was experimentally investigated on the microscopic scale. A thin-section sample, with a dimension of 22×11×3.3 mm (length × width × thickness), was sliced using a trim saw and attached onto a glass slide with epoxy. This sample was composed of two distinguished zones, an organic matter-rich zone and a calcite-rich zone. Iodide containing aqueous-based fluid was used as the source fluid to treat the thin section rock sample from one end. The spontaneous imbibition test was conducted for 100 minutes with one radiographic image taken per minute to capture the dynamic fluid front.
The iodide containing aqueous-based fluid was used in this study to enhance the contrast in microscale radiographic imaging. Microfractures were observed by radiographic imaging in the thin-section sample with 5.48 μm and 2.79 μm resolutions before the fluid treatment, both in the organic matter-rich zone and the calcite-rich zone. Three fluid uptake features have been revealed in this dynamic fluid imbibition study: (1) the fluid moved very fast and reached the other end of the sample in less than 4 minutes in the microfractures within the organic matter-rich zone; (2) the fluid moved very fast and reached the other end of the sample in less than 4 minutes in microfractures within the calcite-rich zone; and (3) in a calcite-rich matrix, the water front progressed very slowly, to about 120 μm penetration in 100 minutes. The fast water uptake through microfractures in the organic-rich zone and fracture networks in the calcite-rich zone correspond to imbibition-controlled transport in the strongly water-wet pore space. The slow water uptake through the calcite-rich matrix could be a combination of weakly water-wet imbibition and slow flow process due to large viscous flow resistance (or small permeability) in small-sized pores.
During the slick water fracturing process in unconventional reservoirs, only a small percentage of fracturing fluids is generally recovered. Where the remaining fluids reside in the formation is still an open question in the industry. This study experimentally reveals that the imbibition into the rock matrix is much slower than into microfractures. Therefore, it is very likely that natural and induced microfractures are the major areas where the fluids remain after the flow back.
Smart Autopilot Drone System for Surface Surveillance and Anomaly Detection via Customizable Deep Neural Network
Authors: Zhai Xiang , Liu Kui , Nash William , Castineira David 
Published: January 2020

Copter-based unmanned aerial vehicle (drone) systems are being utilized for surveillance, inspection and security purposes for well sites, gathering centers, pipelines, refineries, and other surface facilities. However, most of the practices largely rely on humans, including drone operation, data transfer, image analysis, etc. In this paper, we present a comprehensive, cloud-enabled, human-free autopilot drone system and its application in field surveillance and anomaly detection powered by customizable deep neural network and computer vision models.The proposed system consists of customized quadcopter drones equipped with high-definition cameras, thermal imaging and gas sensing devices, autopiloted by cloud-connected onboard computers. A series of advanced algorithms are developed and deployed onboard and over the Cloud for processing and diagnosing the image/thermal/gas sensing data collected by the drones in real-time or near real-time, including accurate 2D geospatial aerial mapping, anomaly detection and classification for events like oil leak, gas leak, facility failure, human activities, etc. Object detection deep learning models are customized and parallelized for low-profile multi-core single board computers.In our case study, a pre-configured drone flew along the same path twice at a 6-month gap. A robust, iterative image registering algorithm is developed to precisely align and overlay images taken at different days at the same or similar GPS locations, even with significant changes to the environment due to season shift, human activities, camera angles or height variations. Local changes are filtered and selected based on their sizes and magnitudes in the residual images by subtracting pairs of perfectly overlaid scenes. Pre-trained Residual Convolutional Neural network (He et al. 2015) is rapidly re-trained to further classify the type of changes using the techniques of transfer learning and data augmentation. An ROC of 99% was achieved in the multi-task binary classification, wherein the detected changes are divided into positive anomalies (such as oil/gas leak, facility failures, unauthored human activities) and negative (natural/insignificant) signals. Comparing against a support vector machine baseline with a ROC=92%, the ResNet model demonstrates significant, more promising detection accuracy at a faster training time.This innovative integrated platform is presented that combines physical drone, onboard imaging/sensing devices, cloud connectivity, onboard and back-end control system, deep learning and computer vision architecture for situational awareness of oil & gas fields and the mining industry. It achieves full automation of mass surveillance, data acquisition and storage, diagnostics and asset situational understanding. The system architecture, especially the onboard and cloud computation engines, can be readily transferred and applied to other common drone platforms.
Deep Reinforcement Learning: Reservoir Optimization from Pixels
Authors: Miftakhov Ruslan , Al-Qasim Abdulaziz , Efremov Igor 
Published: January 2020

The application of Artificial Intelligence (AI) methods in the petroleum industry gain traction in recent years. In this paper, Deep Reinforcement Learning (RL) by pixel data is used to maximize the Net Present Value (NPV) of waterflooding by changing the water injection rate. This work is the first step towards showing that learning from pixel information offers many benefits, for example, understanding the reservoir's physics directly by measuring changes in pressure and saturation distribution without taking into consideration reservoir petrophysical property and the total amount of wells with corresponding locations.
The optimization is tested on the 2D model, which is a vertical section of the SPE 10 model. It has been shown that RL is able to optimize waterflooding in a 2D compressible reservoir with the 2-phase flow (oil-water) by means of pixel data. In the first few thousands of updates, optimization remains in the baseline NPV since it takes more time to converge from raw pixel data than to use classical well production/injection rate information.
The reservoir NPV increased by 15 percent as a result of optimization, where the optimum scenario results in less watercut and more stable production. Additionally, we evaluated the impact of choosing the action set for optimization and examined two cases where water injection well can change injection pressure with a step of 200 psi and 600 psi. The results show that in the second case, AI optimization is exploiting the limitation of the reservoir simulator and tries to imitate a cycled injection regime, which results in a 7% higher NPV than the first case.
A Date Tree Fiber-Based LCM for Severe Loss Control
Authors: Amanullah Md , Alouhali Raed , AlArfaj Mohammed 
Published: January 2020

Different types of conventional and unconventional fibrous LCMs have been used in the design of loss control slurry and/or LCM pill to overcome the loss circulation problems. Almost all of these fibrous LCM products are imported from overseas countries. Hence, the objective of this pioneering research is to develop an eco-friendly fibrous LCM product using a locally available raw materials that has a sustainable source of supply in the Kingdom or in this region to ensure continuous support for exploration and exploitation of oil and gas resources in the region.Review of all locally available natural resources lead to the identification of a sustainable source of high fiber containing raw materials for localization of fibrous LCM production to combat moderate to severe loss of circulation. A physio-mechanical process involving collection, washing, drying, chopping and grinding were used to prepare the fibrous LCM product using the whole date tree wastes. Several widely used water-based muds such as bentonite mud, NaCl-polymer mud, KCl-Polymer mud and CaCl2-Polymer mud were used to evaluate the sealing and plugging performance of the Fibrous LCM. 10 and 30 ppb novel fibrous LCM were added to each mud system and then mixed properly to make a homogenous loss control slurry.Test conducted using PPT apparatus and 2-mm slotted disc at 1500 psi pressure and 250° F temperature showed effective sealing and plugging performance with all the mud systems. Test conducted using a 20-30 mm pebble bed simulating a rubble type super-K loss zone under 100 psi overbalance pressure also showed effective sealing and blocking potential for the newly developed LCM product when incorporated in a 65 pcf bentonite mud. Two high performing commercial LCM products such as STOPLOSS and Soluseal also showed similar performance. However, test conducted with an in-house developed Vug Test apparatus with a 10mm circular hole simulating an equivalent vug showed effective sealing and plugging for the newly developed LCM product. But the two high performing commercial LCM products mentioned before failed to seal the 10-mm vug. This indicates that the newly developed date tree waste-based LCM product has superior sealing and blocking capacity than the commercial products used for comparative evaluation. Hence, it could be concluded that the eco-friendly and biodegradable date palm industry waste can provide a sustainable source of local supply of fibrous LCM product to meet the industry demand.
Mitigating Drilling Hazards in a High Differential Pressure Well Using Managed Pressure Drilling and Cementing Techniques
Authors: Egbe Peter , Iturrios Carlos 
Published: January 2020

Formation pressure heterogeneity in a reservoir can represent a significant challenge when a high overbalance condition is created in a zone with low pore pressure; leading to total losses, and potential stuck pipe events which subsequently increase well costs and non-productive time. This paper describes a case involving high differential pressure between the heel of the reservoir, and toe of the lateral, and where drilling in an up dip direction increased the complexity of the operation.
The original well design considered drilling the entire reservoir section in one 6 1/8–in. section. However, to mitigate identified operational challenges, the 7-in. liner depth was adjusted to cover the high pressure section of the reservoir, thus isolating the weaker reservoir zones at well total depth. Managed pressure drilling (MPD) was deployed to drill both sections to reduce the overall overbalance condition and to provide an additional method to determine the pore pressure. Furthermore, the 7-in. liner was run in MPD mode to minimize the chances of differential sticking; and cemented in place using Managed Pressure Cementing (MPC) technique to mitigate against inducing downhole losses during the cementing operation which would have impacted zonal isolation efficiency, and the long term well integrity leading to possible sustained casing pressures (SCP).
Managed Pressure Drilling (MPD) is an adaptive drilling technique that is used to precisely assess the formation pressure and manage the bottomhole pressure accordingly. MPD allows the use of a lighter mud density to reduce the overbalance condition and by manipulating the annular surface pressure a condition of constant bottom-hole pressure can be maintained. MPD was implemented to determine the formation pressure and define the optimal mud density for the operation during drilling, and while running and cementing the liner, thus mitigating the risk of potential losses and differential stuck pipe.
SOfPD Subsea Pipelines Technical Assessment
Authors: Alanazi Abdullah , Al-Daej Omar 
Published: January 2020

The assessment approach for the study utilized a semi-quantitative risk-based methodology designed to identify, analyze and evaluate risk associated with each subsea pipeline. The risk calculation combines the Probability of Failure (PoF) and the Consequence of Failure (CoF). The PoF calculations considered different factors, which believed to have direct impact on the likelihood of pipelines failure including: internal corrosion, hydrogen induced cracking (HIC) susceptibility and mechanical integrity.
In general, the risks levels are High, Medium-High, Medium and Low. The High and Medium-High risks level is mainly driven by the high CoF due to significant economic and environment impacts and high PoF due to internal corrosion, HIC cracking susceptibility and mechanical integrity. In order to lower the risks both PoF and CoF should be reduced.
Prediction and Mapping of Karst Features in Mishrif Carbonate Reservoir Through Neural Net Process - Zubair Field
Authors: Cossa Alessandro , Guglielmelli Andrea , Rotelli Fabiana , Bazzana Michele , Callegaro Chiara , Raimondi Cominesi Nicola , Bigoni Francesco , Pirrone Marco , Ali Hassan Al Attwi Maher , Ibrahim Uatouf Kubbah Salma 
Published: January 2020

Carbonate reservoirs are often characterized by karst features occurrence, usually related to a significant permeability enhancement in presence of low porosity and low permeability matrix type sediments. The distribution of such karst features is generally highly heterogeneous and difficult to predict, making the reservoir management challenging.
In Zubair Field (Iraq), there are numerous evidences of karst events within the Upper interval of Mishrif Formation. The production behavior of Upper Mishrif is therefore very heterogeneous, moving from wells with relatively low flow capacity, as expected from petrophysical interpretation, to wells with a very high flow capacity, hence related to karst enhanced permeability. The integration of petrophysical interpretation, well test and multi-rate production logging allowed to preliminary highlight the improved permeability intervals associated to karst. In addition, accurate image log analysis on the same wells investigated a possible relationship between vug densities and production data, to be extended also to wells lacking the latter data. This process allowed to define a karst flag in more than 60 wells.
Then, correlations between karst features and different seismic and geological attributes were identified. The most meaningful parameters were used as input data for a Neural Net Process, leading to the definition of a probability 3D Volume of karst occurrence.
The final outcomes of the workflow are karst probability maps, used as a driver for the definition of new wells targets and associated trajectories. The recent drilled wells, with optimized paths according to these prediction-maps, have demonstrated the reliability of this approach intercepting the desired karst intervals. This study represents a valuable opportunity in terms of understanding of the reservoir behavior and impact on the ongoing intensive drilling campaign and related field performance.
Exploring the Multiple Benefits of CSR on Organizational Performance: Case of Lebanon
Authors: Hejase Hussin , Farha Cybelle , Haddad Ziad , Hamdar Bassam 
Published: January 2020

Companies around the globe are recognizing the importance of engaging in Corporate SocialResponsibility (CSR) that is crucial to their survival and growth. It is evident that when anorganization integrates appropriate CSR practices in its strategy that embed the societal andenvironmental concerns, these practices undoubtedly bring tangible benefits to the business alongwith a sustainable competitive advantage.
In Lebanon, there is a consistent need for the Lebanese community to live in a safe, clean andhealthy environment. Companies can no longer act as isolated entities that can run separately fromthe society and the environment in which they operate and with which they interact, disregardingthe impact of their activities on the economy, the society, and the environment; these companies areassuming and acknowledging their responsibility not only towards shareholders through profitmaximization but also towards all stakeholders through enhancing the welfare of the society andadopting environmentally-based behavior.However, there exists a substantial lack of awareness of CSR among Lebanese companies. Thecurrent practices in Lebanon have suffered from the lack of responsible behavior towards theemployees, the economy, the society, and the environment. Consequently, the current researchaddresses the urgent managers’ need to understand what CSR is and assess the multiple benefits ofits programs, and how they may help and end up in a win-win situation if CSR is implementedadequately.
This research is exploratory in nature and uses a survey questionnaire distributed to a convenientsample of Lebanese managers and employees working in Lebanon. The purpose is to assess theknowledge and the implementation of CSR programs at selected number of Lebanese firms. Thisresearch attempts to define the gap between the existing socio-economic and environmentalproblems and the responsiveness levels of Lebanese firms to such problems.