bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Practical Model for Water Injection Evaluation and Optimization in Typical Offshore Reservoirs Considering Formation Heterogeneity Based on Experimental Study
Authors: Huang Shijun , Zhu Yuanrui , Chai Shichao , Ding Guanyang , Xin Yicheng , Li Peiyu 
Published: December 2021

Abstract
A major concern with water injection in offshore oil reservoir is the water breakthrough. The formation heterogeneity is the main reason for it. In order to evaluate the water injection efficiency, a visualized 2-D experiment was carried out to obtain the distribution law of injected water and the variation of injection parameters in homogeneous and heterogeneous formation. In addition, a coupled wellbore/reservoir model was established by applying microelement method, superposition principle and imaging. This model considers the formation heterogeneity and pressure drop caused by wellbore friction. The visualized 2-D sand filling displacement experiment indicates that the injection rate at the horizontal well heel is greater than that at the toe and the injection front is more irregular in heterogeneous formation. The injection rate and injection pressure distribution along the horizontal well are obtained analytically based on the proposed model, the results show that the injection rate at the two sides of the wellbore is much higher than that in the middle when the formation is homogeneous and the wellbore is infinite-conductive. In this case, the injection rate curve along horizontal well shows a "U" shaped distribution. When a finite-conductive horizontal wellbore is considered, the injection rate at the heel of the wellbore is higher than that of the toe, although the injection rate curve along horizontal well also exhibits a deformed "U" shape distribution. For the formation heterogeneities along the horizontal wellbore, the injection rate distribution curve is not continuous anymore, but a deformed "U" shape is also observed for each wellbore segment. At last, the established model was applied to an ultra-heterogeneous offshore reservoir. It is concluded that the profile control effect of typical well is obvious. The results of this study are of great significance for the calculation of the injection rate profile and improving the water injection efficiency.
Autonomous Directional Drilling Planning and Execution Using an Industry 4.0 Platform
Authors: BA Samba , Ignova Maja , Mantle Kate , Chassard Adrien , Yu Tao , Chambon Sylvain , Akkaoui Ziad , Jiang Lu , Harmer Richard , Barcelata Olivia , Kim Jinsoo , Rhazaf Mustapha 
Published: December 2021

Abstract
Today, directional drilling is considered a mix between art and science only performed by experts in the field. In this paper, we present an autonomous directional drilling framework using an industry 4.0 platform that is built on intelligent planning and execution capabilities and is supported by surface and downhole automation technologies to achieve consistently performing directional drilling operations accessible for easy remote operations.
Intelligent planning builds on standard planning activities that are needed for directional drilling applications and advances them with rich data pipelines that feed predictive and prescriptive machine-learning (ML) models; this enables more accurate BHA tendencies, operating parameters, and trajectory plans that ultimately reduce executional risk and uncertainty.
Intelligent execution provides technologies that facilitate decision-making activities, whether they be from the wellsite or town, by leveraging the digital-drilling program that is generated from the intelligent planning activities. The program connects planning expectations, real-time execution data from the surface and downhole equipment, and generates insights from data analytics, physics-based simulations, and offset analysis to achieve consistent directional drilling performance that is transparent to all stakeholders.
This new framework enables a self-steering BHA for directional drilling operations. The workflow involves an automated evaluation of the current bit position with respect to the initial plan, automated evaluation of the maximum dogleg capability of the BHA, and the capability to examine the health of the BHA tools and, if needed, an automated re-planning of an optimized working plan. This is accomplished on a system level with interdependencies on the different elements that make up the complete workflow.
This new autonomous directional drilling framework will minimize operational risk and cost-per-foot drilled; maximize performance, procedural adherence, and establish consistent results across fields, rigs, and trajectories while enabling modern remote operations.
Methodology of Effective Lateral Placement for Underbalanced Coiled Tubing Drilling Wells
Authors: Abdul Aziz Azly , Moreno Sierra Ferney , Aldossary Nawaf 
Published: December 2021

Abstract
This paper describes a methodology that has been developed to maximize lateral placement in productive reservoir intervals during underbalanced coiled tubing drilling (UBCTD) operations. UBCTD has emerged as an effective and economically viable development solution for exploiting reserves in mature gas reservoirs. In some cases, it can be a suitable solution to develop reserves in more geologically complex and heterogonous reservoirs over the conventional drilling and stimulation techniques.
The methodology integrates big surface and subsurface data from multiple sources in multiple formats in real to near real-time that are normally acquired during UBCTD drilling operations. The multiple sources of data include subsurface geology, wellsite biosteering, reservoir influx, well testing and drilling, and can provide important information about the reservoirs encountered. With the aid of data analytics and an advanced visualization tool, the data is translated into in series of engineering plots that enable easier identification of productive intervals and more informed as well as efficient lateral placement decisions. This methodology has proven superior to the conventional instantaneous Productivity Index (PI) approach that is commonly used for UBCTD lateral placement.
The methodology has been tested with good success in a number of recently drilled UBCTD wells in geologically complex depositional environments across carbonates and clastic reservoirs. Post flowback and pressure transient test analyses have shown significant improvement in the well deliver abilities and effective lateral lengths. Past performance from wells drilled using the PI method will be compared with wells drilled with this method.
Surfactant Polymer SP vs. Alkali-Surfactant Polymer ASP: Do We Need the a in ASP?
Authors: Delamaide Eric , Rousseau David , Wartenberg Nicolas , Salaun Mathieu 
Published: December 2021

Abstract
The first surfactant-based pilots can be traced back to the 1960s and since then almost a hundred field tests have taken place. Interestingly, almost half of these pilots have used an alkali (ASP) and the other half has not (SP). This reflects the current status of the industry which is divided along the same lines and over the same question: do surfactant-based processes require alkali or not? This paper proposes to address this question by providing explanations and discussing case studies.
The paper will start by reminding the reader of the role of both surfactant and alkali and will review the pros and cons of alkali in terms of formulation performances, adsorption but also surface facilities and logistics. Several cases studies (lab and field) will be discussed to show when alkali can and cannot be used, and what solutions are available as alternatives to the use of alkali.
Although alkali allows reducing both surfactant concentration and adsorption, it can also cause severe scaling and requires additional facilities including water softening; in addition, the large volumes of alkali required can cause logistical challenges. On the other hand, the main challenges of formulations without alkali is finding surfactants that can develop a low enough Interfacial Tension and low adsorption, or to find an acceptable adsorption mitigation strategy such as salinity gradient or adsorption inhibitors. In the early years of SP projects, very high surfactant concentrations were used (micellar process) and the process was not economic; as a result, alkali was seen as the only realistic solution. This appears to no longer be the case due to the developments of new surfactants. Although most projects in recent years have favoured the use of alkali, it seems that a trend towards SP is growing, with recent field projects in Kuwait, Oman, China and Russia favouring the SP solution.
This paper will provide a discussion on the pros and cons of the use of alkali in surfactant-based processes. It will show that although using alkali has been a standard for many years it also entails severe surface issues such as scaling and requires additional capital for water softening and logistics. More importantly, recent developments in surfactants now seem to provide alkali-free solutions that can compete in terms of formulation performances. This now needs to be confirmed in the field.
Accurate Live Interfacial Tension for Improved Reservoir Engineering Practices
Authors: Okasha Taha , Al Hamad Mohammed , Sauerer Bastian , Abdallah Wael 
Published: December 2021

Abstract
Current reservoir simulators use interfacial tension (IFT) values derived from dead oil measurements at ambient conditions or predicted from literature correlations. IFT is highly dependent on temperature, pressure and fluid composition. Therefore, knowledge of the IFT value at reservoir conditions is essential for accurate reservoir fluid characterization. This study compares IFT values from dead and live oil measurements and the results of literature predicted values, thereby clearly showing the weakness of existing correlations when trying to predict crude oil IFT. A total of ten live oils was sampled for this study. Using the pendent drop technique, IFT was measured for each oil at different conditions: in the under-saturated region at reservoir pressure and temperature, in the saturated region at reservoir temperature, and for dead oil at ambient conditions. Basic PVT properties such as gas to oil ratio (GOR), gas and liquid composition, density, viscosity and molecular weight were also measured. The bubble point for each oil was identified to define the pressure step in the saturated region for extra IFT measurement. The equilibrium IFT values for the live oils were generally higher than for the corresponding dead oils. For oils where this general trend was not observed, contaminations were found in the crude samples. The use of current literature correlations does not allow to predict correct reservoir IFT. Therefore, this study provides accurate live IFT values for a variety of reservoir fluids and conditions in combination with live oil properties, highly beneficial to reservoir engineers, allowing better oil production planning.
NanoGram Detection of Drilling Fluids Additives for Uncertainty Reduction in Surface Logging
Authors: Zhu S. Sherry , Antoniv Marta , Poitzsch Martin , Aljabri Nouf , Marsala Alberto 
Published: December 2021

Abstract
Manual sampling rock cuttings off the shale shaker for lithology and petrophysical characterization is frequently performed during mud logging. Knowing the depth origin where the cuttings were generated is very important for correlating the cuttings to the petrophysical characterization of the formation. It is a challenge to accurately determine the depth origin of the cuttings, especially in horizontal sections and in coiled tubing drilling, where conventional logging while drilling is not accessible. Additionally, even in less challenging drilling conditions, many factors can contribute to an inaccurate assessment of the depth origin of the cuttings. Inaccuracies can be caused by variation of the annulus dimension used to determine the lag time (and thus the depth of the cuttings), by the shifting or scrambling of cuttings during their return trip back to the surface, and by the mislabelling of the cuttings during sampling. In this work, we report the synthesis and application of polystyrenic nanoparticles (NanoTags) in labeling cuttings for depth origin assessment. We have successfully tagged cuttings using two NanoTags during a drilling field test in a carbonate gas well and demonstrated nanogram detection capability of the tags via pyrolysis-GCMS using an internally developed workflow. The cuttings depth determined using our tags correlates well with the depth calculated by conventional mud logging techniques.
Field Assessment of Camera Based Drilling Dynamics
Authors: Koulidis Alexis , Abdullatif Mohamed , Abdel-Kader Ahmed Galal , Ayachi Mohammed-ilies , Ahmed Shehab , Gooneratne Chinthaka , Magana-Mora Arturo , Affleck Mike , Alsheikh Mohammed 
Published: December 2021

Abstract
Surface data measurement and analysis are an established mean of detecting drillstring low-frequency torsional vibration or stick-slip. The industry has also developed models that link surface torque and downhole drill bit rotational speed. Cameras provide an alternative noninvasive approach to existing wired/wireless sensors used to gather such surface data. The results of a preliminary field assessment of drilling dynamics utilizing camera-based drillstring monitoring are presented in this work.
Detection and timing of events from the video are performed using computer vision techniques and object detection algorithms. A real-time interest point tracker utilizing homography estimation and sparse optical flow point tracking is deployed. We use a fully convolutional deep neural network trained to detect interest points and compute their accompanying descriptors. The detected points and descriptors are matched across video sequences and used for drillstring rotation detection and speed estimation. When the drillstring's vibration is invisible to the naked eye, the point tracking algorithm is preceded with a motion amplification function based on another deep convolutional neural network.
We have clearly demonstrated the potential of camera-based noninvasive approaches to surface drillstring dynamics data acquisition and analysis. Through the application of real-time object detection algorithms on rig video feed, surface events were detected and timed. We were also able to estimate drillstring rotary speed and motion profile. Torsional drillstring modes can be identified and correlated with drilling parameters and bottomhole assembly design. A novel vibration array sensing approach based on a multi-point tracking algorithm is also proposed. A vibration threshold setting was utilized to enable an additional motion amplification function providing seamless assessment for multi-scale vibration measurement.
Cameras were typically devices to acquire images/videos for offline automated assessment (recently) or online manual monitoring (mainly), this work has shown how fog/edge computing makes it possible for these cameras to be "conscious" and "intelligent," hence play a critical role in automation/digitalization of drilling rigs. We showcase their preliminary application as drilling dynamics and rig operations sensors in this work. Cameras are an ideal sensor for a drilling environment since they can be installed anywhere on a rig to perform large-scale live video analytics on drilling processes.
Scaling Formulae for the Wellbore Hydraulics Similitude with Drill Pipe Rotation and Eccentricity
Authors: Nosar Thad , Khodaparast Pooya , Zhang Wei , Mehrabian Amin 
Published: December 2021

Abstract
Equivalent circulation density of the fluid circulation system in drilling rigs is determined by the frictional pressure losses in the wellbore annulus. Flow loop experiments are commonly used to simulate the annular wellbore hydraulics in the laboratory. However, proper scaling of the experiment design parameters including the drill pipe rotation and eccentricity has been a weak link in the literature. Our study uses the similarity laws and dimensional analysis to obtain a complete set of scaling formulae that would relate the pressure loss gradients of annular flows at the laboratory and wellbore scales while considering the effects of inner pipe rotation and eccentricity.
Dimensional analysis is conducted for commonly encountered types of drilling fluid rheology, namely, Newtonian, power-law, and yield power-law. Appropriate dimensionless groups of the involved variables are developed to characterize fluid flow in an eccentric annulus with a rotating inner pipe. Characteristic shear strain rate at the pipe walls is obtained from the characteristic velocity and length scale of the considered annular flow. The relation between lab-scale and wellbore scale variables are obtained by imposing the geometric, kinematic, and dynamic similarities between the laboratory flow loop and wellbore annular flows.
The outcomes of the considered scaling scheme is expressed in terms of closed-form formulae that would determine the flow rate and inner pipe rotation speed of the laboratory experiments in terms of the wellbore flow rate and drill pipe rotation speed, as well as other parameters of the problem, in such a way that the resulting Fanning friction factors of the laboratory and wellbore-scale annular flows become identical. Findings suggest that the appropriate value for lab flow rate and pipe rotation speed are linearly related to those of the field condition for all fluid types. The length ratio, density ratio, consistency index ratio, and power index determine the proportionality constant. Attaining complete similarity between the similitude and wellbore-scale annular flow may require the fluid rheology of the lab experiments to be different from the drilling fluid. The expressions of lab flow rate and rotational speed for the yield power-law fluid are identical to those of the power-law fluid case, provided that the yield stress of the lab fluid is constrained to a proper value.
Production Performance Analysis of Western Siberia Mature Waterflood with Prime Diagnostic Metrics
Authors: Aslanyan Arthur , Margarit Andrey , Popov Arkadiy , Zhdanov Ivan , Pakhomov Evgeniy , Garnyshev Marat , Gulyaev Danila , Farakhova Rushana 
Published: December 2021

Abstract
The paper shares a practical case of production analysis of mature field in Western Siberia with a large stock of wells (&gt; 1,000) and ongoing waterflood project.
The main production complications of this field are the thief water production, thief water injection and non-uniform vertical sweep profile.
The objective of the study was to analyse the 30-year history of development using conventional production and surveillance data, identify the suspects of thief water production and thief water injection and check the uniformity of the vertical flow profile.
Performing such an analysis on well-by-well basis is a big challenge and requires a systematic approach and substantial automation.
The majority of conventional diagnostic metrics fail to identify the origin of production complications. The choice was made in favour of production analysis workflow based on PRIME metrics, which automatically generates numerous conventional production performance metrics (including the reallocated production maps and cross-sections) and additionally generates advanced metrics based on automated 3D micro-modelling.
This allowed to zoom on the wells with potential complications and understand their production/recovery potential.
The PRIME analysis has also helped to identify the wells and areas which potentially may hold recoverable reserves and may benefit from additional well and cross-well surveillance.
Quadrant Mapping Artificial Lift Concept
Authors: Rohman A. F. , Febriana C. , Sany S. , Hanggoro R. E. 
Published: December 2021

Abstract
This paper outlines a concept for monitoring performance of artificial lift performance such as electrical submersible pump (ESP), hydraulic pumping unit (HPU), sucker rod pump (SRP) and progressive cavity pump (PCP), for a large number of wells. The objective is to generate simplified monitoring performance of artificial lift with a huge number of wells on one page by creating quadrant mapping consisting of two coordinates with x axis representing pump efficiency and y axis showing pump submergence. We made a four-quadrant limit by pump efficiency (50%) and submergence (200 m). Optimum wells will show on range pump efficiency above 50% and submergence below 200 m, and 3 other quadrants are classified as artificial lift problems, well potential and sizing/design problems.
By using the quadrant mapping concept, we can generate performance of artificial lift for 1500++ wells in one page, and this mapping consists of four quadrants (quadrant 1, quadrant 2, quadrant 3 and quadrant 4), quadrant 1 (Submergence above 200 meter and lifting efficiency below 50%) showing wells which have artificial lift problem, quadrant 2 (Submergence is above 200 meters and efficiency is above 50%) showing well which have potential to increased production, quadrant 3 (Submergence is below 200 meters and efficiency is above 50%) showing the optimum wells operation and quadrant 4 (Submergence is below 200 meters and efficiency is below 50%) showing the wells which required to re-sizing/re-design artificial lift.
This quadrant mapping can be shown to Engineers, manager's and shareholder to show overall performance and classification detailed problems to create a troubleshooting, optimization program to increased oil production, run life artificial and result in better production performance. This mapping also helps petroleum engineers to get a better field view and create priorities and program optimization based on the quadrant mapping result and classification.