bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating Efficiency of Surfactant-Polymer Flooding with Single Well Chemical Tracer Tests at Kholmogorskoye Field
Authors: Bondar Mikhail , Osipov Andrey , Groman Andrey , Koltsov Igor , Shcherbakov Georgy , Milchakov Sergey
Published: December 2021

EOR technologies in general and surfactant-polymer flooding (SP) in particular is considered as a tertiary method for redevelopment of mature oil fields in Western Siberia, with potential to increase oil recovery to 60-70% OOIP. The selection of effective surfactant blend and a polymer for SP flooding a complex and multi-stage process. The selected SP compositions were tested at Kholmogorskoye oilfield in September-December 2020. Two single well tests with partitioning chemical tracers (SWCTT) and the injectivity test were performed.

The surfactant and the polymer for chemical EOR were selecting during laboratory studies. Thermal stability, phase behavior, interfacial tension and rheology of SP formulation were investigated, then a prospective chemical design was developed. Filtration experiments were carried out for optimization of slugs and concentrations. Then SWCTT was used to evaluated residual oil saturation after water flooding and after implementation of chemical EOR in the near wellbore areas. The difference between the obtained values is a measure of the efficiency of surfactant-polymer flooding. Pandemic restriction shifted SWCTT to the period when temperature dropped below zero and suitable for winter conditions equipment was required.

Two SWCTT were conducted with same surfactant, but different design of slugs in order to prove technical and economic models of SP-flooding. Long-term polymer injectivity was accessed at the third well. Oil saturation of sandstone reservoir after the injection of a surfactant-polymer solution was reduced about 10% points which is around one third of the residual oil after water flooding. Results were compared with other available data such as well logging, lab core flooding experiments, and hydrodynamic simulation. Modeling of SWCTT is ongoing, current interpretation confirms the increase the oil recovery factor after SP-flooding up to 20-25%, which is a promising result.

Temperature model of the bottom hole zone was created and verified. The model predicts that temperature of those zones essentially below that average in the reservoir, which is important for interpretation of tracer test and surfactant efficiency. The tested surfactant showed an acceptable efficiency at under-optimum conditions, which is favorable for application of the SP formulation for neighboring field and layers with different reservoir temperatures, but similar water composition. In general, the results of the conducted field tests correlate with the results of the core experiments for the selected surfactant
Digital Integration, Success Story of Accelerating Business Integration of Two Biggest Midstream-Downstream Natural Gas Company in Indonesia
Authors: Mujiyanto Arief , Wicaksono Agung , Adhi Fonny Prasmono , Missuari Muhammad Subhan
Published: December 2021

To achieve 24% portion of natural gas in targeted national energy mix in 2050, Indonesia government has integrated Pertagas, biggest transmission company into PGN, biggest distribution company under Oil & Gas Holding Pertamina. But survey from PWC in 2004 resulted that around 75% post-merger companies reported integration difficulties, especially both companies have long history of competition. Even more, government mandated 6 USD gas price policy at plant gate, which create enormous urgency to accelerate pipeline and digital integration in the most efficient way. Especially, in this pandemic era, midstream industry needs to foster digital transformation by rethinking outdated business models and strategically applying technology to change rather than focusing on simply cutting costs.

From this integration, Pertagas with more than 2,418 km pipeline in 12 provinces spread from Sumatra, Java and Kalimantan has a big potency to be synergized with PGN, as Sub Holding Gas with the total of 10,169 km of pipeline which represent 96% of national gas infrastructure. During 2020. Both companies resulted more than 1.255 MMSCFD of transported gas and 828 BBTUD of sales gas to more than 460 thousand customers. So, PGN and Pertagas management has high expectation on this digital integration to transform from previous fragmented pipeline to be interconnected network to give flexibility in reaching unmet growing demand of strategic industry like refinery, fertilizer, electricity, steel and petrochemical in post-COVID recovery.

In this paper, will be described the challenges and its solutions as a success story in digital integration. The important steps start from strategy development, digital assessment, creating coalition, culture acculturation, and change management are explained as guiding pathway for sustainable implementation. It will also portray the measured benefit and value from investment cost efficiency, time effectiveness from the initiation until launched, billing improvement, product development, and up to developed real-time integrated management dashboard for better decision making and part of the milestone for future National Dispatching Center for optimizing Sub Holding Gas portfolio of gas supply and subsidiary's infrastructure to meet growing Indonesia's demand.
Blockchain and 6G-Based Supply Chain Management Framework for Oil and Gas Shipment
Authors: Rahman Md Abdur , Belal Syed M.
Published: December 2021

Keeping track of the oil and gas supply chain is challenging task as the route and transportation requires sophisticated security environment - both physical systems’ and IT systems’ security. Thanks to the recent advancement in IoT, specialized sensors can keep track of the required supply chain environment. With the help of blockchain, the supply chain data can be immutably saved for further sharing with stakeholders. Due to the introduction of AI as an embedded element within 6G networks, the end-to-end supply chain process can now be automated for safety, security, and efficiency purposes. By leveraging 6G, AI, blockchain, and IoT, the supply chain data during the transportation or at rest can be monitored for any changed environment during the movement of the ship through national or international routes. In this paper, we study the requirements of such intelligent and secure supply chain management system conducive to the oil and gas industry. We also show our proof-of-concept implementation and initial test results. Our obtained results show promising prospect of the current system to be deployed to safeguard the oil and gas supply chain.
Infinite Water: Implementation of Nanofiltration for Optimization of Vessel Stimulation Operations in the Offshore Greater Ekofisk Area, North Sea
Authors: Kusumawati Irma , Edward Bremner Samuel , McIntosh Neil , Nylend Ingrid , Rajkovic Tanja
Published: December 2021

The incorporation of a sulfate removal system onto a stimulation vessel has been shown to positively affect vessel utilization, increase efficiency in field development, and reduce freshwater consumption.

Stimulation vessels have fixed storage and transportation volumes as well as a fixed total mass that can be loaded. Fresh water occupies the highest proportion of space and mass in most stimulation treatments, which imposes limitations on all other products that can be loaded out. Particularly for acid stimulation treatments, a compromise between the volumes of raw acid and fresh water must be made in order to achieve the best operational efficiency possible.

Any method that can reduce, eliminate, or replace fresh water as a component in stimulation fluids will have a significant impact on vessel efficiency. One option is the use of seawater as the base fluid. However, seawater can cause problems for well production due to the high sulfate content in the water leading to the formation of mineral scale. The solution to this problem has been the installation of a sulfate removal system on the stimulation vessel. Driven by membrane nanofiltration, this system can produce up to 100 m3/hr of low sulfate water from seawater for well stimulation operations. By removing the scaling risk from seawater, this system enables the stimulation vessel to maximize the products it loads with the ability to produce low sulfate water as and when it is needed.

The sulfate removal system can reduce SO4 content to 4.3 mg/l and reduce other ions present in seawater. With an output of 100 m3/hr and being installed independently from stimulation systems, the unit is able to produce water regardless of ongoing activities. In stimulation jobs, multistage ball drop operations are the most time-critical operations. In the analysis of hundreds of stages stimulated with water from the new nanofiltration system, the average stage completion time was 6 hours, which included ball loading, dropping, and displacement; diagnostic injection testing; and the main treatment. With an average water requirement of 600 m3, the vessel can keep up with water demand and remove water capacity from the utilization equation.

The use of a compact nanofiltration system for SO4 removal has improved stimulation vessel operations where scale production is a key concern for operators. In addition to increasing vessel utilization and intervention efficiency, the system will lead to the elimination of approximately 68,000 m3 of fresh water being pumped every year for stimulation operations in the North Sea.
GRE Lined OCTG as a Cost-Effective Solution for Water Disposal Wells
Authors: Pimenta Gervasio , Ahmad Mohamad Hussain , Mizukami Akio , Andres Bogdan
Published: December 2021

Glass Reinforced Epoxy (GRE), lining systems for API 5CT tubing have gained prominence in O&G industry, essentially due to the fact that GRE constitutes a physical barrier protecting the OCTG pipe from corrosive environment, and minimizing issues with scale deposition.

ADNOC group companies have been building experience on the implementation of GRE Lined L-80 tubing by successfully using it in produced water disposal wells.

Produced water is a highly corrosive medium due to dissolved CO2, H2S high to very high chloride content, high TDS, eventually containing bacteria. The corrosiveness of the fluid increases as the temperature increase from temperatures in the range of 30 – 50 degC at surface to reservoir temperature. The aggressiveness of this medium towards API 5CT L-80 or 13Cr / modified 13Cr increases with its contamination with oxygen. Dissolved oxygen is a strong depolarizer leading to high pitting rates if dissolved O2 content in the water is above 10 or 20ppb.

Conventional completion of WDW in ADNOC Onshore is based on API 5CT L-80, and short life of the completion strings has been attributed to deficient water treatment (lack of oxygen scavenger, corrosion inhibitor unsuitable for downhole conditions.

A life cycle cost analysis suggests that GRE lined OCTG could be a cost-effective solution for water injection. For this life cycle cost assessment, CAPEX (cost of L-80 completion string, combo corrosion inhibitor & oxygen scavenger skid and OPEX: cost of Combo chemical and monitoring activities for design life were considered, while achieving the required level of well integrity and lower operational safety risks (e.g. handling hazardous chemicals, monitoring activities)
3D Multi-Level Facies Constrained Geostatistical Inversion for Predicting Carbonate Thin Reservoirs
Authors: Guo Tongcui , Dou Lirong , Wang Guihai , He Dongbo , Wang Hongjun , Zhang Jian , Liu Weiliang
Published: December 2021

Carbonate reservoirs are highly heterogeneous and poor in interwell connectivity. Therefore, it is difficult to predict the thin oil layers and water layers inside the carbonate reservoir with thickness less than 10 ft by seismic data. Based on the petrophysical analysis with core and well logging data, the carbonate target layers can be divided into two first level lithofacies (reservoir and non-reservoir) and three second-level lithofacies (oil, water and non-reservoir) by fluids. In this study, the 3D lithofacies probabilistic cubes of the first level and second-level level lithofacies were constructed by using the simulation method of well-seismic cooperative waveform indication. Afterwards, constrained by these probability cubes, the prestack geostatistical inversion was carried out to predict the spatial distribution of thin oil layers and water layers inside the thin reservoir. The major steps include: (1) Conduct rock physics analysis and lithofacies classification on carbonate reservoirs; (2) Construct the models constrained by two-level lithofacies; (3) Predict thin reservoirs in carbonates by prestack geostatistical inversion under the constraint of two-level lithofacies probability cubes. The prediction results show that through the two-level lithofacies-controlled prestack geostatistical inversion, the vertical and horizontal resolution of thin oil layers and water layers in carbonate reservoirs has been improved significantly, and the accuracy of thin oil reservoir prediction and the analyzing results of interwell oil layer connectivity have been improved significantly. Compared with the actual drilling results, the prediction results by 3D multi-level lithofacies-controlled inversion are consistent with the drilling results, and the details of thin carbonate reservoirs can be predicted. It has been proved that this method is reasonable and feasible. With this method, the prediction accuracy on thin reservoirs can be improved greatly. Compared with the conventional geostatistical inversion results, the 3D multi-level lithofacies-controlled inversion can improve significantly the vertical and horizontal resolution of prediction results of thin reservoirs and thin oil layers, and improve the reliability of interwell prediction results. For the prediction of thin carbonate reservoirs with serious heterogeneity, the 3D multi-level lithofacies-controlled inversion is an effective prediction method.
First Ever Gas Simops Implementation In Abu Dhabi Offshore: A Success Story
Authors: Al Hammadi Majid Ismail , Scheed Andreas , Alsabri Hasan , Al Ali Hasan , Al Obaidli Yaqoub , Ismail Jawed , Abdel Ghani Khalid , Ba-Aqeel Yahya , Eltaher Alaa , Kumar Pramod , Varghese Mario , Jaorawala Ammar , Mohammed Riyas , Chennallour Shabbeer , Ratnakar Venugopal , Junaidi Abang , Amr Mostafa , Elarngal Sathyanarayan
Published: December 2021

Gas SIMOPS is a concurrent execution of two or more activities at same time, i.e., Drilling Operation, Oil Production & Gas Injection on an offshore wellhead tower thereby ensuring uninterrupted oil production and continuous reservoir pressure management from gas injection. The alternative to gas injection in this scenario was gas flaring, which has major environmental and financial impact. Considering continuous presence of personnel on drilling rig working over wellhead tower with high pressure gas injection; extensive Risk Analysis were conducted, and additional control/Mitigation measures were implemented.

This initiative also contributed to the zero Gas flaring vision of the company by achieving a huge quantity of CO2 emission reduction. This successful Gas SIMOPS model is already being extended to other fields.

To achieve this objective and keeping with 100% HSE, an in-house multi-disciplinary team collaborated and successfully executed Gas SIMOPS for the first time in UAE Offshore.

Execution of Gas SIMOPS has brought major economic benefits to the company with additional Gas savings incurred.
Petroelastic Model PEM for a Highly Heterogeneous Cretaceous Reservoir in Middle East
Authors: Celma Rafael Ignacio , Singh Nepal , Ouldamer Kamal , Debec Pascal
Published: December 2021

The objective of this project is to simulate elastic logs (sonic P, sonic S and density) through a Petroelastic Model (PEM) for a complex lithology reservoir in the Middle East, that later will be used as input for a new 4D seismic feasibility study. A log conditioning (despike, depth shift, hydrocarbon correction and normalization) and comprehensive petrophysical analysis was first performed, to obtain lithology volumetric, porosity and saturation, that later were used as input for the PEM. Some wells with recorded P and S sonic log were used to conduct different cross plots of elastic properties (e.g. Vp/Vs vs. Acoustic Impedance) in order to understand how lithology, porosity and saturation affect the elastic parameters of the reservoir. After understanding and assessing the elastic behavior with the reservoir properties, three approaches to construct a PEM were tested on this reservoir. The first approach used to construct PEM applying Hashin Shtrikman (H-S) mixt, considering the solid part as a mixture of dolomite and limestone and pore space filled with a mix of oil and water. This model is limited because assumes a homogenous geometry of the pores. To address the pore geometry a Kuster Toksoz (K-T) approach was subsequently tested but the challenge was that there was no clear organization of the aspect ratio (either by lithofacies or petrophysical groups) so the original logs were used to control of the aspect ratio trough a fit function. The third approach was to use a function that models the incompressibility model of the frame (Kdry) with porosity. The result of H-S was a good agreement in the low porosity areas but in the porous intervals, it is observed that the velocities were quite high due the effect of the pore geometry that was not properly assessed by H-S. Despite reasonable reconstructions, K-T was limited by the impossibility to apply it to the wells without sonic P and S (uncalibrated aspect ratio) or a fortiori to a 3D grid. For the Kdry vs. Porosity function the result was very successful since the function is not dependent on the pore geometry, and addresses the ratio issue between solid and pore space. Then with the help of the Gassman Equation, the final Incompressibility Mix Module (Kmix) was calculated and a reconstructed sonic P and S were available for all the wells. The PEM was coded in order to deploy over a 3D property model hence a volumetric elastic model was available to assess the feasibility for new seismic acquisition.
Smart Archive Generation Using Computer Vision, NLP and Big Data
Authors: Marzouk Mohamed Mahdy , ElZahed Mahmoud Mohamed
Published: December 2021

Gaining insights from the dense network of interrelated documents involved in E&P projects requires experience, knowledge, and awareness about the existence of the required data. This framework aims to facilitate the decision-making process while consuming shorter time periods and lower costs, without sacrificing the accuracy of the data and decreasing the probability of human errors. The high complexity of E&P Projects results in a dense network of interrelated documents which are produced to cover the various aspects and details of the project. Gaining insights from old data requires experience, knowledge, and awareness about the existence of the required data. Accordingly, the knowledge accumulated over the time from various projects can be considered a key asset, since it can be leveraged to perform more informed decisions. This paper presents a framework that aim at capturing organizational knowledge locked in paper-based datasets and store it in a structured digital format that facilitates its retrieval and enables analyses which help uncover valuable insights. This research aims to generate valuable data from existing archives while causing minimal disturbance to existing business processes and workflows. The framework performs four main functions: image processing, text recognition, Data Analytics and Data storage. Initially the text recognition module; which is performs Image Processing to enhance the quality of the scanned files, and optical character recognition using LSTM which extracts the text contained in images. The Data Analytics Module, then cleanses and mines the extracted text using Big Data Analytics tools. Text Matching and searching is performed on the Spark Dataframe using regular expressions to identify different attributes and their different types. Finally, the data is stored in a SQL Database. In order to measure the workflow's accuracy a manual baseline was generated for a sample project. The accuracy is measured using field-level verification, since it was found to be the most fit-for-purpose, as it allows to measure the accuracy of the workflow on the level of each field.
Digitally Enabled Organizations- Leveraging New Age Technologies
Authors: Srivastava Yogesh Chandra , Srivastava Abhishek , Granata Consuelo
Published: December 2021

When inadequate information appears via a long-winded channel, project leaders usually struggle to make timely decisions. There is frequently a lack of visibility, contractual and organizational fragmentation, and genuine facts being segregated and concealed due to an optimism bias. Despite the finest planning and estimation efforts, projects frequently exceed their budgets or experience delays of more than 30%. The paper outlines the importance of data and of data use to improve the performance in projects planning and delivery. The data value and hierarchy are reviewed in the context of the construction industry and the importance of a smooth digitalization process for ensuring acceptance and adoption is discussed. The concept of ‘digital construction blocks’TM and Lean thinking is introduced to address the problem of complexity which is commonly recognized as the main cause of cost overruns, time delays, and poor quality and safety for the construction industry.

To capture the footprint of how the asset was built, the authors propose the Digital Twin of Execution adding dynamism to the commonly discussed Digital Twin of Asset, which is more static when the asset has already been constructed. The project is organized into digital blocks, allowing all project functions and disciplines to focus on a common path of construction, allowing for an earlier start of a constraint-free construction and, as a result, de-risking and compressing the total execution schedule. Data from existing systems and technologies is unlocked and placed in automated processes, allowing thousands of documents, activities, and fast-moving events to be collected in digital blocks of construction. The digital block is connected throughout project stages and taken across all aspects of the project, including plot plans, activity plans, drawings, 3D, materials, and so on, resolving the project's disarray caused by manual and analogue procedures. The entire planning, project setup, and execution process is aided by GIS, which provides visibility at various levels of magnification via an interactive geo spatial map superimposed with plot plans, timetables, and work packages. Artificial intelligence (AI) and machine learning (ML) can be used to forecast the probability of danger in various field operations. It's done by using IoT devices implanted in employees’ PPE and in the environment to process data collected on the system. Digital Control Tower can provide a smart dashboard that not only displays the KPIs but also helps the user prioritize his next steps. It may provide an overall view of the project's progress and KPIs, as well as get to the root of a problem in a specific installation area, raise red flags and alerts, and function as a user's assistant by predicting errors early on.
Root Cause Analysis of Wells with Integrity Failures
Authors: Yugay Andrey , Pimenta Gervasio , Zhukin Aidar , Daghmouni Hamdi Bouali , Silchenok Mikhail , Bongiovanni Corrado , Al Mohammed Edries Ibrahim , Ahmad Mohamad Hussain , Abdulsallam Fouad , Alam Mufti Sagirul
Published: December 2021

A Root Cause Analysis (RCA) is a methodological process of problem solving. In brief, this is an approach of "post mortem" analysis of the consequences with aim to understand what is one single (or multiple) lack of Management System that led to failure. Subsequently we can develop detailed remedial plan and actions to address failed Management System and most importantly prevent reoccurrence. Approach has been widely used in science and engineering. Probably, will be difficult to identify inventors of this analysis however first appearance in engineering discipline credited to Sakichi Toyoda, founder of Toyota Industries. He improved RCA by implementing technique called the "5 whys".

Despite obvious benefit and versatility of root cause analysis methodology there are several challenges that might jeopardize result:–Absence of critical data / information due to various reason (time gap, no recoverable samples etc)–Too many variables that not allow to pinpoint main line / chain of investigation–Multiple failures with different root causes–"Depth of investigation" how many "Whys" are efficient to reveal main root cause.
Acceleration of Novel Technology Development for Stabilized Emulsion Treatment in EOR Applications
Authors: Mohd Sahak Muhammad Zakwan , Myo Thant Maung Maung , Saadon Shazleen , Krebs Thomas , Verbeek Paul , Akdim Mohamed Reda , Villacorte Loreen
Published: December 2021

Separation of stable emulsions produced from chemical enhanced oil recovery (CEOR) in a brownfield production system using conventional 3-phase separators is almost impossible, requiring large quantities of chemical demulsifiers to meet oil production specifications. A new and novel high-voltage high-frequency (HVHF) electro-coalescence (EC) technology has been identified as potential method to enhance separation of EOR produced fluid for improving CEOR implementation feasibility. This paper aims to present results and findings from the recent EC technology development against success criteria and parameters associated for fast-track field application. Electrostatic coalescers are used as an emulsion breaker, crude dehydrator or desalter in production systems and refineries. However, significant developments are required to use this EC technology as a potential treatment technology for tight emulsions/rag layers in CEOR applications. A new prototype of Inline EC was developed and tested in a batch test setup to evaluate the separation efficiency using real crude-brine samples and a cocktail of alkaline-surfactant-polymer (ASP) chemicals. The sensitivities of separation efficiency to different water cut, demulsifier concentration, EC voltage/exposure time, concentrations of alkaline, surfactant and polymer in the brine were measured and optimal process conditions were assessed. The results and findings were evaluated based on defined success criteria and parameters associated with separation efficiency such as volume fractions of the emulsion, oil-in-water (OIW) and water-in-oil concentrations (WIO), respectively. On one of PETRONAS CEOR field case study, the test results show that EC reduced 90% of the tight emulsion. In conclusion, EC leads to a substantial improvement in separation efficiency relative to the case without EC for water cuts below the inversion point. It is also found that the EC treatment without added demulsifier is equally effective in breaking the emulsion as adding a demulsifier without EC treatment, and that EC can potentially minimise or eliminate the application of demulsifiers in the production system.
Miscible WAG Efficiency Assessment on a Large Mature Carbonate Field
Authors: Bourgeois Marcel J. , Berrahmoun Hocine , Al Attar Maryam Mohamed , Boulenouar Djilali , Hammadi Djelloul , Romero Carolina , Shi Wen , Torrez Maria Fernanda
Published: December 2021

This paper is based on the analysis of miscible WAG for an onshore Middle-East field, with strongly undersaturated light oil. Water Alternate Gas operations have been ongoing for around 5 years, which is relatively recent compared to more than 40 years of production history. Goal of this work was to assess the efficiency of this miscible hydrocarbon WAG and to optimize it on the different compartments, with respect to miscibility, voidage replacement, and recycling.

As this is a large mature field, with WAG operations dispatched on around 50 injectors and 9 fault blocks (compartments), the method of analysis had to be robust with respect to the different injection strategies followed in the past. It was essentially based on injection and production data, but also used pressure data when available. We computed the following dimensionless variables: oil recovery factor, BSW, voidage replacement ratio (VRR), and also WAG ratio and gas recycling ratio (GRR). Their evolution versus time was analyzed and compared between fault blocks.

Using dimensionless variables allowed to compare fault blocks with different initial volumes in place, and to illustrate trends versus time. It was also found beneficial to lump some compartments, when communication was substantiated by pressure data. On the production side, we used the conventional BSW and GOR variables to quantify the water and gas recycling ratio. On the injection side, we observed that in some compartments, the historical WAG ratio was too low in the oil zone, which could be quantified by excluding the peripheral water injection volumes.

The analysis allowed also to estimate the gas utilization factor and efficiency, which confirmed the overall high efficiency of miscible gas injection in 3-phase mode. It was also found that the injected fluid efficiency correlated with geology: gas injection tends to be more efficient in zones with high permeabilities at the bottom (coarsening downwards), while water injection is better adapted to zones with high permeabilities at the top (coarsening upwards). Estimating these water and gas efficiencies also allowed to optimize the injection strategy on a field level, by comparing the water efficiency with other units of the field only under waterflood.
Application of Successful New Downhole Fluid Sampling Technique in Ultra Low Permeability Reservoir in Abu Dhabi Onshore
Authors: Khairy Hamad A , Soliman Ahmed M , Elabsy Islam M , Syofyan Syofvas , Nestyagin Andrey , Al-Shabibi Tareq A , Fauzi Tengku Mohd , Telang Viraj Nitin , Fraquet Javier A , Coskun Sefer B
Published: December 2021

Downhole reservoir fluids sampling in tight formations has been a continuous challenge due to various reasons. The paper presents a technique of successfully collecting downhole fluid samples for first time in ultra-low permeability reservoir having a history of deep invasion. This became possible by initiating micro-scale fractures followed by pumping out for sampling. Using this technique, downhole formation fluid samples were collected, clean-up time was optimized, in addition to acquiring in-situ stress information during the process.

A preliminary assessment was performed using open hole formation evaluation logs and pore pressure measurements to identify the most suitable zones for stress measurement and fluid sampling. Single packer sleeve fracture initiation tests were performed to break down the high stress dense layers. In the reservoir rock, the stress measurement involving initiation of a micro-scale fracture was followed by pumping out formation fluid from the fractured zones to collect clean formation fluid samples.

The formation breakdown and fracture closure pressure were measured successfully to calibrate minimum and maximum lateral tectonic strains which were valuable inputs for designing the hydraulic fracturing treatment. In the offset wells, fluid sampling attempts from this zone of interest have proven unsuccessful after multiple attempts involving pumping out over 300 liters because of the high depth of invasion leading to a thick flushed zone around the wellbore. The process of initiating micro-scale fractures followed by pumping out provided a high permeability flow channel for efficient fluid sampling. The near wellbore fractures resulted in pumping at higher rates and reaching the higher oil saturated zones of this deeply invaded formation. Hence, formation fluid samples were successfully collected in spite of the low permeability and high invasion typically encountered in this reservoir.

Unlike the unsuccessful sampling attempts in the offset wells, this technique of initiating micro-scale fractures in the reservoir rock followed by pumping out helped in collecting formation fluid samples. This technique can be used to collect reservoir fluid samples from micro-Darcy formations and unconventional reservoirs by improving the flow through the induced fractures and thereby reducing the uncertainty that may persist in failing to collect samples from such zones.
Novel In-Line Inspection Tool for Deposit Characterization in Pipelines
Authors: Lehtikangas Ossi , Voutilainen Arto , Nissinen Antti , Laakkonen Pasi , Cyriac Sinoj , Tienhaara Mika
Published: December 2021

Deposition formation inside pipelines is a major and growing problem in the oil and gas industry. The optimal use of prevention and remediation tools such as chemical inhibitors and cleaning processes could lead to major savings due to minimized production problems and optimized pipe cleaning costs. This requires characterization and quantification of the actual deposits inside pipelines and downholes. Recently, a novel deposition inline inspection sensor moving inside the pipeline has been proposed based on "inside-out" electrical tomography. In this sensor, the distribution of electrical properties between the sensor and the pipe wall are estimated based on measurements carried out using electrodes around the sensor. In this study, the next generation sensor moving inside the pipeline is described and a deep neural network based approach to deposit estimation is introduced. Test results from a 70 m long semi-industrial scale flow loop containing paraffin wax and calcium carbonate deposits of different thicknesses are shown. Challenges include the changing position and orientation of the sensor during the low. The results show that the sensor is able to measure both deposit thickness and type with good accuracy which indicates that the sensor is suitable for industrial use. Accurate knowledge about deposits allows future blockage prevention, detecting build-up locations in the early phase, increasing accuracy of multi-phase flow and deposition models, optimization of chemical use and validation of deposit cleaning tools before integrity campaigns leading to overall reduced pipeline operation costs.
Evaluation of Foam-Gels for Conformance Control in High Temperature High Salinity Carbonates
Authors: Almaskeen Lyla , AlSofi Abdulkareem , Wang Jinxun , Kaidar Ziyad
Published: December 2021

In naturally fractured reservoirs, conformance control prior to enhanced oil recovery (EOR) application might be essential to ensure optimal contact and sufficient sweep. Recently, few studies investigated combining foams and gels into what is commonly coined as foamed-gels. Foamed-gels have been tested and shown to be potential for some field conditions. Yet, very limited studies were performed for high temperature and high salinity carbonates. Therefore, in this work, we study the potential of foamed-gels for high temperature and high salinity carbonates. The objective is to evaluate the potential of such synergy and to compare its value to the individual processes.

For that purpose, in this work, we rely on bulk and core-scale tests. Bulk tests were used for initial screening. Wide range of foam-gel solutions were prepared with different polymer types and polymer concentrations. Test tubes were hand shacked thoroughly to generate foams. Foam heights were then measured from the test tubes. Heights were used to screen foaming agents and to study gelant effects on foamers in terms of foam strength (heights). The effect of foamers on gelation was evaluated through bottle tests. Based on the results, an optimal concentration ratio of gelant to foamer was determined and used in core-scale displacements, to further study the potential of this hybrid foam-gel process.

Bulk results suggested that addition of the gelant up to a 4:1 foam to gel concentration ratio resulted in sufficient foam generation in some of the polymer samples. Yet, only two of the foam-gel samples generated a strong gel. Increasing the foamer concentration delayed the gelation time and in some samples, the solution did not gel. Through the coreflooding experiment, resistance factor (RF) and residual resistance factor (RRF) were obtained for different conformance control processes including foam, foam-gel, and gel. Foam-gel injection exhibited higher RF and RRF values than conventional foams. However, conventional gels showed even higher RF and RRF values than foam-gels.

Combining two of the most widely used conformance control methods (foams and gels) can strike a balance. Foam-gel may offer a treatment that is deeper and more sustainable than foams and on the other a treatment that is more practical, and lower-cost than gels. Our laboratory results also demonstrate that such synergetic conformance control can be achieved in high salinity and high temperature carbonates with pronounced impact.
What the Shale are We Talking About!
Authors: Hoxha Besmir Buranaj , Rabe Claudio
Published: December 2021

Shale ‘stability’ has been extensively studied the past few decades in an attempt to understand wellbore instability problems encountered while drilling. Drilling through shale is almost inevitable, it makes up 75 percent of sedimentary rocks. Shale tends to be characterized as having high in-situ stresses, fissile, laminated, with low permeability. However, not all shale are the same, and the problem herein lies where they are all treated as such, in which most cases, has shown to be ineffective. Ironically, shale is predominantly generalized as being "reactive/swelling". Even though this can be true, it is not always the case because not all shale is reactive! In reality, there are many different types of shale: ductile, brittle, carbonaceous, argillaceous, flysch, dispersive, kaolinitic, micro-fractured etc. This study aims to clear many misconceptions and define different types of shale (global case scenarios) and their failing mechanisms that lead to wellbore instability, formation damage and high drilling cost. Afterwards, solutions will be offered, from a filed operation perspective, which will provide guidelines for stabilizing various shale based on their failure mechanism. Furthermore, we will define the symptoms for shale instability and propose industry accepted remedies.
Efficient Drilling Technology of Horizontal Wells in the Duverney Block in Canada
Authors: Han Haochen , Yang Guobin , Zhang Guobin , Chen Jia , Chen Peter , Fu Jin , Wang Siqi
Published: December 2021

Recent years, both exploration and development have made considerable progress in the Duverney block shale gas in Canada. However, technical problems exposed in horizontal drilling engineering need to be optimized: 1) Loss is common in shallow formations; 2) High downhole friction torque, low ROP and drilling cuttings accumulation in long horizontal well section; 3) Borehole instability leads to hanger or packer failure; 4) Drill bits and PDM have short servicing life and low efficiency.

Optimization comes from three aspects: (1) Based on previous drilling experience and latest formation condition and development requirement, we design a new well profile for the block taking into drilling safety and further development account;(2) Optimize strong inhibitive, easy-maintenance and high cutting-carrying capacity OBM to ensure the safety requirements in the ultra-long open hole section; (3) BHA and parameters optimization. Optimize drill bit with high-abrasiveness and axial efficiency according to logging data, drillability and UCS. Upgrade conventional PDM into high-performance PDM with even-wall thickness. By means of simulation and calculation, drilling parameters suitable for Duverney block has been optimized.

Based on the optimization above, a stable and efficient well profile has been improved solving hanger failure on-site efficiently and complete with composite casing design (4-1/2 inch plus 5 inch) in reservoir section; a 90/10 oil-water ratio OBM has been optimized and applied onsite; Combined with high performance PDC bit and even-wall PDM as well as optimized drilling parameters, higher ROP and longer horizontal section have been achieved. The optimization has made successful field application results:(1) Completion depth has been deepened gradually, from 18,080 ft in 2013 to 23,208 ft at present, with an increase of 28.3%;(2) Horizontal section length has been increasing dramatically, from 6,190 ft in 2013 to 10,301 ft at present, with an increase of 66.4%;(3) The average drilling cycle has been shortened, from 51 days in 2013 to 26 days at present, with a decrease of 48.8%;(4) The average ROP has increased steadily, from 71.2ft/h in 2013 to 82.12ft/h at present, with an increase of 15.3%; (5) Drilling costs per meter have been significantly reduced, from 442.4 CAD/ft in 2013 to 228.3 CAD/ft at present.

Combining the optimization and matching design above, it has effectively solved the difficulties of the Duverney block drilling engineering and achieved good field application effects: well depth and horizontal section length in the block have been deepened year by year, the drilling cycle and cost have been decreased year by year, as well as the economic effect has been significant. In all, the research achievements provide a practical and effective reference for horizontal wells in other region especially for the unconventional gas.
Successful Approach in Curing Lost Circulation in Depleted Aquifer Formations by Utilizing a Combination of Swelling Polymer & a Shear-Rate Rheology-Dependent Cement System; Case Study in UAE Land Operation
Authors: Saragi Raymond , Husien Mohammad , Sinaga Agus Liber Maradat , Mwansa Peter Levison , Varma Esha Narendra , Hussain Mohamed Qassem , Rocha Michelle C. Santos , Nasrallah Mena , Mohamed Sherif , El Saad Rashad Abo
Published: December 2021

One of the greatest historically unsolved challenges to date in the United Arab Emirates is the failure to effectively cure the severe losses due to poor zonal isolation during drilling and cementing aquifer formations in particular the Dammam, UER & Simsima formations in the BAB field. Continuous efforts have been made to seek and pilot new technologies in UAE land operations to overcome drilling operation challenges, specifically chronic lost circulation in aquifer formations with the commitment to drive a more cost-effective operation and reduce the risk of Non-Productive Time (NPT). The current practice was not providing proper zonal isolation in the surface and intermediate sections. Most of the time aerated drilling was utilized while drilling the lost zones and conduct a top-up cement job to improve zonal isolation, but this results in limited reliability. It was necessary to identify a different approach to cure or significantly reduce the losses which would enable the hole section to be drilled successfully while minimizing operational risks, in a cost-effective manner.

A technique combining two different technologies was selected: a swelling polymer lost-circulation material (LCM) that hydrates and helps reduce flow velocity into the formation, followed by a shear-rate rheology-dependent cement system. This cement system is a tunable and tailored slurry with thixotropic properties and has shown very cost-effective results with high success rates. It was then decided to tailor this approach to Abu Dhabi land operations to maximize wellbore asset value. After four subsequent trials targeting two different aquifer formations, the technique has shown tremendously promising results by successfully curing the losses providing above 80% returns. These combined technologies aim to eliminate or reduce effect of losses during cementing by performing the primary cementing job with complete returns or minor losses across aquifers thus enhancing wellbore integrity during the lifecycle of the well. It is hoped that this will eliminate, or at a minimum reduce production deferrals and subsequently improve plug and abandon (P&A) operations at end of field life.

This paper aims to describe the challenges faced on the first three trials utilizing this technique and the solutions assigned for each trial based on the inputs, such as loss rate, formations interval exposed, design and lab testing for the pumped treatments as well as job execution details along with lesson learned for future jobs.
Integrated Stochastic Inversion Approach Assessing Thin Reservoirs Full Potential in the Prolific Oil-Prone Periphery of Hassi Messaoud Field, Algeria
Authors: Tawfik Mohamed Samy , Nasrine Medjdouba , Annou Sabiha , Ahcene Aiouna , Haddouche Abderaouf , Barling Thomas , Kenef Mohamed
Published: December 2021

Nowadays it become harder, risker and more expensive understanding the reservoir potentiality and design the optimum development plan for challenging thin reservoirs. In a geological complex area, integrated seismic reservoir characterization approach was crucial to unlock the potentiality for the study area, which is located at Oued Mya basin, SE Saharan platform Algeria.

Seismic data analysis is one of the key procedures for characterizing reservoirs and monitoring subsurface properties. Integration of seismic stochastic inversion and geological model will help to demonstrate the link between seismic and reservoir properties more quantitative. The seismic data of region were challenging, with around 30 wells drilled over 400 Km2. To overcome the challenges, the available geological and geophysical data were integrated to construct the reservoir characterization study and reduce drilling uncertainty.

Ensure the reservoir characterization process was constrained by a robust workflow and consistent with the available geophysical, geological, and petrophysical data. Petrophysical interpretation, seismic interpretation, rock physics analysis and Stochastic Inversion processes were carried out. These processes were integrated to characterize the lateral and vertical extent of the lithofacies in five stacked reservoirs across the area of interest to identify the potential delineation of thin reservoirs of nine-meter thickness.