bluuebunny/crossref_metadata_2025 huggingface dataset:
Delivering an Innovative Active MPD Wellbore Sealing System for Field Operations
Authors: Johnson Austin , Sundaramoorthy Saravanan , Ameen Kareem , Nichols Jess , MacGregor Alex , Fraczek Justin
Published: November 2020

Objectives/Scope

This paper shares results from the first field deployment of an active sealing device in a narrow margin deepwater well in the Black Sea. The active sealing device represents a clean-sheet design approach purpose built for deepwater MPD operations. This paper shares highlights from the detailed design through the prototype testing to the first-use stages of the program.

Methods, Procedures, Process

This paper discusses three distinct program phases covering the overall process from concept development to field operation. First, the detailed design phase is discussed, introducing the reader to system components and functionalities. The second phase of full-scale testing is discussed from the design verification, system optimization, and systems integration testing perspectives. Finally, field results are shared detailing findings from the first deployment on a dynamically positioned deepwater rig drilling a narrow margin MPD well in the Black Sea.

Results/Observations/Conclusions

The paper shares findings, insights, and results from each of the phases of the active sealing device development program.Upscaling passive RCD technology for deepwater has negative effects on system performance.A non-rotating, externally functioned seal sleeve element eliminates multiple high wear components.Elimination of bearing assemblies and rotary seals removes common failure modes seen in deepwater.Redundant, actively controlled seal elements ensure wellbore seal quality throughout the seal life.A lubrication system injects mud between seal elements, enabling seal condition monitoring.Active seal condition monitoring alerts the rig crew when to replace the elements prior to failure.Full-scale testing has been completed demonstrating the system under simulated drilling conditions.Seal life demonstrated to outlast most deepwater MPD hole sections.Operational testing and integration testing reduce commissioning and testing time consumed on the rig.Active sealing device successfully integrated into the drilling riser and MPD specialty joint.Multi-modal system provides rig crew with distinct operational strategies to meet current parameters.Consistent seal life enables rig crew to drill MPD sections with confidence in the wellbore seal.Deepwater well with multiple MPD sections successfully drilled using new active sealing device.

Novel/Additive Information

The project includes secondary novel aspects such as drilling contractor ownership of the subsea and topside MPD equipment. The MPD system is integrated into the drilling control system allowing communication between the rig, subsea, MPD topsides, and all third-party systems, while also sharing commonality with other rigs in the fleet. An objective of the MPD system design is to enable new models of fleet management to meet drilling contractor operations.
Multi-Functional Production Unit for Marginal Fields
Authors: Thiruthonder Haravinth , See Kiat Chin
Published: November 2020

With soaring global demand, depleting supplies of crude oil coupled with the collapse in the oil prices, maximizing oil production in mature fields has become a priority. Such fields account for over 70% of the world's oil and gas production, with a worldwide average recovery factor of 35% for oil. Main challenge encountered by mature oil fields is the well pressure depletion over time, sand production and increased water-cut. Since pressure depletion is inevitable, it is particularly challenging to continue to produce as there is insufficient reservoir pressure to push the well fluids to the main processing facilities. As the reservoirs starts to deplete, other issues such as sand production and high water cut also becomes more prominent.

The system discussed in this paper is an effective engineering solution designed for topside receiving facilities. The Multi Production Unit (MPU) is a low pressure production unit with integral desanding and dewatering. MPU is a system tailored to boost the pressure of production fluids from low pressure wells, while handling common challenges in mature fields such as high water cut and high sand production. The system is ideally suited for remote wellhead platforms where wells have insufficient pressure to deliver well fluids to production header in addition to flow assurance issues related to high sand and water production.

Conceptual design of this system is based on the very low, almost atmospheric, operating pressure of the system, wherein the elements. The system is designed in such a way that it can receive continuous full flow from the well, and still manages–through intricate isolation methodology-to operate in batches. This batch operation arrangement allows for liquid accumulation which is then discharged to the production header after being pressurized. The integral desander enables sand removal from the production fluid before discharging the liquids to the production header. The accumulated sand can be discharged in batches whilst the system continues to produce. The dewatering feature of the system allows for removal of water prior to discharging the oilflow from the well to topside becomes easier without the need to inject the well itself with any foreign, resulting in reduced induced backpressure due to reduction in flow to the downstream system.

Features of the system include:Compact design;Light weight;Self-contained system – no external utilities required except for HP gas source for motive gas and instrument gas/air supply;No pumps and power generation;Low system complexity and controls;Fully automated systemNo manning requirement;Sand handling; andBulk water handling.
4D Seismic for Integrated Reservoir Characterisation
Authors: Tan Aaron Qun , Chia Jessica , Thiam Flora , Ting Angelina Jia
Published: November 2020

A case study on the integration of 4D seismic with various multi-scale and multidimensional field data to understand dynamic behaviour of the reservoirs is presented.

4D seismic is a key dataset amongst others e.g.geochemical fingerprinting, well inflow tracers, injection logging tools/production logging tools, and multi-well pressure deconvolution) together withconventional field data, which is acquired since starting up the field in late-2016. 4D data proved to be an essential piece that complemented field observations and is integral for constraining the subsurface models in support of a rapid second pahse of development and WRFM decisions. The paper describes the approaches taken to integrate these distinct datasets in the dynamic model as well as the various challenges faced in assimilating them in a coherent manner.

One key subsurface challenge is to understand the degree of compartmentalisation risk to make sound WRFM decisions and to plan for a robust phase 2 development. As a starting point, conventional field performance analysis (production & injection performance) indicated connectivity across the reservoirs, though more limited in certain areas. This was supplemented with other subsurface data to further validate and improve the dynamic models. The 4D signals provided an indication of pressure and fluid connectivity as well as an indication of water sweep direction. Updates to the dynamic fault seal were performed in line with observations from 4D seismic and various field data.

Understanding the dynamic behavior of the M field is key in view of the various challenges faced in reservoir management, e.g. increasing GOR trends and lower WI performance, in parallel with developing plans for the Phase 2 development. The incorporation of data of different scales and dimensions (4D seismic, fluid chemistry, PLT, multi-well pressure deconvolution) added value to the process of updating the dynamic models.
Revolutionising Formation Evaluation in Low Mobility Reservoirs of India
Authors: Ali Ahmed Moge , Ghosal Debdeep , Singh Shreya , Haldia Bhopal Singh , Chaturvedi Praveen
Published: November 2020

Formation testing has been widely prevalent in the industry for critical information, such as reservoir pressure, gradient analysis, and fluid identification, that aids formation evaluation. This paper focuses on the successful evaluation of low-mobility reservoirs using the 3D radial probe as compared to the conventional probe in a comprehensive study of 60 wells (most of them offshore) across India. One of the major challenges in formation evaluation, fluid flow from any interval is not certain. Prospective zones are encountered that lie in unconsolidated sands where critical drawdown pressure cannot be exceeded because of formation integrity issues or there are zones that have low mobility and thus cannot be tested. Reliable pressure results cannot be obtained from these formations, nor can the fluids in these zones be identified because of poor flow potential. To overcome this major challenge, different probe (tool inlet) configurations are used that increase the flow area and help test tight formations (e.g., the 3D radial probe). In this study, 1754 stations were analyzed across several heterogeneous formation types and multiple operators to verify the diverse applicability of the 3D radial probe. The analysis was conducted in two phases. Formation testing results from the first phase showed that 47% and 68% of the points of interest in 2018 and Q1, Q2 of 2019, respectively, across all wells remained unevaluated with the conventional probe. Even among the points that gave valid results, there were low-mobility points where downhole fluid analysis (DFA) was not possible because of poor flow potential. Upon introducing the 3D radial probe in six wells, the shortfall of the conventional probe was overcome, which ultimately contributed to 35% additional evaluation success in 2018. In a comparison of the performance on the same wells and same formations, 3D radial probe fluid identification success in 2019 was 93% compared to 2% success in conventional probe evaluation in these tight reservoirs. Through this study, the uncertainty of fluid typing in the tight reservoir was resolved. Accurate interval permeability values were determined and were input to well deliverability estimates. The 3D radial probe results also help the drillstem test (DST) design, saving significant well cost because wet intervals are avoided using downhole fluid characterization, which revolutionizes formation testing in tight reservoirs.
Value Creation Transformation from a Reactive Workflow to a Proactive and Predictive Monitoring in Real Time Centre
Authors: Arriffin Muhammad Faris , Norhashimi Lokman Bin , Richard Bobbywadi Bin , Mohamad Azlan Bin , Meor Hashim Meor M.
Published: November 2020

Drilling operation real-time centre is envisaged to move forward from having a reactive workflow to being a proactive and predictive monitoring centre. Future state of a fully capable wells real-time centre will systematically integrate previously isolated and underutilized well engineering systems and applications and implement big data analytics by manipulating machine learning algorithm to automate recognition of potential non-productive time incidents. Current setup of real-time centre is presented and compared with future framework corresponding to service delivery process map, real-time system architecture, drilling data flow, and applications which include interventions protocol. Service delivery process map will progress from a directly linear to a close-loop integrated workflow. Applications and databases integration in a single platform on cloud will constitute a two-way connectivity of real time actual measured versus simulated and historical data for an enriched predictive monitoring of drilling operations via established machine learning algorithm. The machine learning algorithm will perform symptom analysis and automation of flag tagging to recognize potential events with inputs from existing combination of static and dynamic monitoring. This data driven approach is capable of leveraging on unprecedented amount of data to provide unbiased algorithm with rigorous trainings. Dynamic monitoring drilling system allows dynamic drilling parameters to be observed continuously and generates cutting simulations to forecast hole conditions and dynamic equivalent circulating density. Running along these systems is the technical limit and benchmarking tool which creates numerous key performance indicators for improvement in drilling operations and pushing well engineering design to its technical limit. The implementation of these systems indicates that intelligent wells systems are achievable in the future by virtues of having enhanced and relevant information available at the opportune moment to help deliver time, cost and effort savings.
Development of Underwater Laser Wire-Filling Welding Device and Welding Maintenance Technology for Offshore Oil and Gas Pipeline
Authors: Zhu Jialei , Jiao Xiangdong , Wang Kai , Gu Yanhong , Cai Zhihai
Published: November 2020

In view of the problems of underwater wet laser welding, such as power attenuation, poor surface forming and narrow adaptability of welding water depth, the defects and causes of wet laser welding are expounded. The local dry underwater laser wire filling welding process is proposed to improve the quality of weld and increase the applicable of water depth. In order to verify the feasibility of the local dry underwater welding process, the quality and characteristics of the welds are compared and analyzed. The experimental results show that the local dry method can effectively increase the water depth and improve the welding quality, and the main mechanical properties of the weld are equivalent to that in the air welding.

With the increasing development of offshore oil and gas resources, there are more and more construction and maintenance of offshore oil and gas equipment. Underwater welding is one important part of underwater maintenance technology for offshore engineering equipments. At present, underwater welding uses mainly arc welding. With the increase of water depth, the environment pressure of underwater arc welding gradually increases, the reliability of arc welding gradually decreases, however, the welding quality and stability cannot be guaranteed [1]. As a new emerging technology of automatic welding maintenance, underwater laser welding is becoming a widely concerned underwater repair technology for offshore engineering. This is due to its advantages such as good accessibility of welding position, high welding quality and little impact of environmental pressure. Compared with the conventional underwater arc welding, the underwater laser welding has the advantages of little influence of environmental pressure, good accessibility of welding position, wide range of welding materials, high welding quality and low residual stress [2,3]. At present, there are two underwater laser welding methods: wet method and local dry method. The cost of wet underwater laser welding is low. This method is flexible, because the welding process is simple, and there is no need to add drainage device or protection device. However, due to the special underwater welding environment, there are complex factors such as high welding pressure, rapid cooling of weldments and high hydrogen content in welds. Therefore, it is difficult to obtain high-quality welds by wet welding [4]. Therefore, the local dry drainage device is designed and used to drain the water from the specimen surface in this experiment, and the underwater laser welding is carried out at the same time.

In order to study the quality and performance of underwater laser welding, the weld quality of wet welding and local dry underwater welding are compared and analyzed. Specifically, the macro morphology, microstructure, hardness, mechanical properties and fracture morphology, and the effects of water depth and local drying environment on weld quality are studied.
Experimental Study on Novel Composite Aicd
Authors: Pan Hao , Cao Yan Feng , Huang Hui , Xu Hao Dong
Published: November 2020

In order to delay the water breakthrough and reduce water production once breakthrough occurs in the bottom water reservoirs, the water control mechanism of novel C-AICD is studied.

The paper describes the laboratory testing of C-AICD, AICD and ICD performed to evaluate the performance of C-AICD and the differences between C-AICD, AICD and ICD. Results from single phase experimental flow testing are presented and discussed.

The testing was conducted in a dedicated flow facility with water, oil and mixed phase fluild. It is under the same experimental conditions to test the water control effect of ICD, AICD, and C-AICD and be analyzed based on the recorded pressure and flow rate data.

The testing results showed that C-AICD could take advantage of AICD and ICD. It could function as a passive ICD to achieve uniform inflow at the beginning of production, and then function as AICD to autonomously restrict water production in the middle and late stages.

Based on a water control design and simulation of one horizontal well, it is found that the comprehensive water-cut of C-AICD well in the production life is about 13% lower than that of the common screen well, which provides a new technical method for economic and effective water-control in oil fields.
Feasibility Study of Dual-Function Chemical in Reducing Surfactant Adsorption and Interfacial Tension for Chemical Enhanced Oil Recovery Application
Authors: Md Akhir Nur Asyraf , Abd Hamid Afif Izwan , Mohd Saaid Ismail , Idris Ahmad Kamal , Nik Norizam Nik Nor , Yusof Nik Kamarulzaman
Published: November 2020

The performance of a low-cost and biodegradable dual-function chemical was evaluated based on its attainment in reducing the interfacial tension and surfactant adsorption in the synthetic seawater at the temperature of more than 90°C. The phase behaviour, interfacial tension, and static adsorption tests have been conducted for the feasibility study of dual-function chemical for the chemical enhanced oil recovery application. The experimental matrices were constructed using Design Expert. Anionic and amphoteric surfactants have been identified for the study to be tested with the dual-function chemical at the temperature more than 90°C in the synthetic seawater. In the phase behaviour study, the volume ratio of the aqueous phase to the Malaysian crude oil was kept 1:1. The interfacial tension between the surfactant and dual-function chemical system against the crude oil was performed by using a spinning drop method. Meanwhile, the static adsorption was conducted by using the crushed core at room temperature up to 30 days, the analysis was conducted by using High-Performance Liquid Chromatography (HPLC) method. In comparison with two types of surfactants; the dual function chemical works best with the anionic surfactant in order to reach the ultralow interfacial tension (less than 10-3 mN/m) within 60 minutes. The ultralow interfacial tension for amphoteric surfactant can only be obtained at an earlier time. In contrast, the phase behaviour study for anionic and amphoteric surfactants and dual-function chemical obtained was a Type II(-) microemulsion. In the static adsorption study, the dual-function chemical (>0.5 wt.%) significantly helps in reducing the adsorption of anionic and amphoteric surfactants up to 73%. Based on the obtained results, dual-function chemical works efficiently when compounded with anionic surfactant than amphoteric surfactant at the same surfactant concentration and reservoir conditions.
Optimisation Design for Pipeline Free Span Mitigation
Authors: Dai Xuexin , Patonico Francesco , Patil Kiran , Goh Kia Hock
Published: November 2020

Pipeline free span mitigation is an integral part of field developments and their design for shallow water conditions poses a number of challenges which require special considerations. This paper discusses the main aspects of pipeline free span mitigation in shallow water conditions as is the case for the Arabian Gulf Region in which the water depths could be close to the limits of applicability of the conventional design codes based on experiences for other regions.

Free span mitigation design according to conventional codes will induce tremendous quantities of intervention works. An optimization design procedure is developed to minimize the number of IWs without compromising pipeline's integrity. Part of the procedure is the implementation of a finite element model which can capture the main features of on-bottom roughness analysis, e.g. pipe-soil interaction and residual lay tension etc. The whole process from pipeline laying on the seabed to operating are simulated. Post-process tools are developed for prompt visualization of the span profiles at different stages to provide efficient judgement for design of mitigation scheme.

The predicted spans from the FE model are compared with as-laid survey spans and good agreement is found, w.r.t locations and span lengths. Sensitivity studies have been performed to investigate the effect of various parameters on pipeline span length. The optimization design procedure constitute mainly three aspects. Firstly, allowable span length (ASL) can be increased by eliminating over-conservatism. The second aspect is reducing span lengths by various approaches, e.g. increasing concrete coating thickness, optimizing the residual lay tension and micro re-routing etc. Lastly, new optimization philosophy is also proposed, which is based on fatigue analysis for the entire design life of pipeline instead of screening by ASL for as-laid condition. Total fatigue damage during as-laid and operating conditions are calculated and compared with allowable value. For locations with total fatigue damage less than allowable value, IWs are not required. The material and installation costs are thus saved without compromising pipeline integrity.

To date, few studies have fully addressed the free span mitigation in shallow water regions. The optimization design procedure and extensive results in this paper will be a good reference for free span mitigation in shallow water regions. This will have direct cost and schedule impact on the execution of brown field developments where crossings and free span mitigation constitute a major element of the project.
Transient Pressure Analysis in Multi-Stage Fractured Horizontal Wells from Tight Gas Reservoirs with Weak Fluid Supply
Authors: Chen Zhiming , Zhang Jiali , Shi Luming , Zhao Juan , Yuan Lijia , Yi Xinbin , Wang Tianyi
Published: November 2020

This paper develops a novel WFS model for transient pressure analysis in multi-stage fractured horizontal wells. In the WFS model, two concepts called WFS pressure and WFS index are introduced and an additional skin factor in the interface of inner and outer regions is applied based on a radial composite reservoir. Then, a novel multi-stage fractured horizontal well model is developed by considering the WFS, stress-sensitivity effects, and finite-conductivity fractures. The reservoir model is solved by the perturbation transformation, Laplace transform, and numerical inversion. While the fracture model is solved by fracture discretization and superposition principle. Finally, the bottom hole pressure is obtained. Following that, model verification and sensitivity study are performed. It is found that the flow regimes of the WFS model includes bilinear flow, linear flow, first radial flow, bi-radial flow, pseudo radial flow, and WFS flow. An interesting feature of "hump" caused by WFS flow exhibits in the pressure derivative curve. The results of sensitivity study show that the height of that "hump" increases as the WFS pressure increases, but is independent of WFS index. What’s more, WFS flow exhibits a closed boundary flow when the WFS index is equal to zero, while it appears as a constant pressure boundary flow when WFS pressure is very tiny. Through the WFS model, the fluid supply characteristics of tight gas reservoirs are fully understood.
Innovative Down-Hole Chemicals Conveyance System with Built in Dual Steering Wheels, First in Onshore Kuwait
Authors: Abdalla Mustafa Al-Hussaini , Al-Kandari Hamad , Al-Meshwet Saad , Telang Milan Kumar , Gowelly Mostafa , Hassan Rabea
Published: November 2020

Produced fluids, from a tight deep carbonate reservoir extended laterally from West to South East Kuwait experienced severe asphaltene deposition along production tubing. This flow assurance challenge significantly increases well operating cost, risk and production deferment periods due to frequent Coiled Tubing (CT) cleaning jobs using considerable amount of expensive organic solvents.

This flow assurance challenge is caused mainly due to the absence of any of strong reservoir aquifer support, continuous decline in reservoir pressure and high draw down across this tight reservoir in order to meet production targets.

The objective of this pilot trial was to provide a long term solution with redundancy feature to convey chemicals safely from surface to down-hole through capillary tubes and pressure regulated chemical injection valves. Different techniques have been introduced since 1980 including batch chemical squeeze treatment, coated tubulars and Radio Frequency Vibration tools. Results of these trials have shown either short term production gain or no improvement on asphaltene build-up rate and well productivity.

In order to dynamically mitigate this challenge, a dual in-situ chemical injection system was installed to convey chemicals deep inside the well on a continuous basis. The system was successfully installed and has provided a safe & reliable field qualifying tool to verify chemical performance at different injection parameters.

The novelty of this technology is the ability to provide a continuous asphaltene management system to achieve production sustainability using dual injection conduits and down-hole pressure regulated valves utilizing relatively small amount of chemicals.

This paper highlights the adopted approach of continuous asphaltene management system from hardware design & installation prospective to chemical qualifying process in the field and also shed light on the pilot trial lessons learned.
Risk-Free Delivery of Production Chemicals to Deepwater Oil and Gas Fields
Authors: Grutters Mark , Kuzniarek Justin , Jackson Steven
Published: November 2020

Uninterrupted delivery of production chemicals through umbilicals and capillary strings is absolutely critical for oil & gas operators to avoid build-up of solids in wells and flowlines as well as excessive corrosion of the subsea infrastructure. However, flaws in design, poor installation and maintenance of subsea chemical injection systems, or deviating from operational procedures can cause blockages or leaks.

In this paper two case histories will be provided about chemical injection failures. One failure is related to the formation of gas hydrates in the umbilical due to malfunctioning of an injection valve. The other failure occurred due to delivery problems due to high viscosity. Some information will be shared on why these failures could occur and improvements to the qualification process to avoid this in the future.

Several deepwater operators and service companies developed chemical selection criteria based on the guidelines and recommendations from the 2007-2011 "Blockage Avoidance in Subsea Injection and Control Systems" (BASICS) JIP. Many companies have incorporated these recommendations in a subsea qualification process for deepwater chemicals. Chemical injection failures often relate to mechanical failure or limitations to the subsea injection system rather than to the chemical itself – especially after the JIP recommendations were incorporated. However, a qualified chemical product may cause injection problems if a holistic review of the application is lacking. The case histories will demonstrate the criticality of collaboration between the operator, engineering company and suppliers; sharing system information and operational conditions avoids costly mistakes.

The complexity of deepwater chemical qualification is to design experiments that reliably predict field performance from lab testing. Moreover, failure mechanisms, e.g. corrosion, gunking and polymerization, are slow processes and laboratory experiements have to be accelerated to much shorter timescales for chemicals to be deployed quickly in the field to treat the risks they are designed for. With the deepwater boundaries getting pushed to new limits some of the laboratory testing has to be redesigned to assess the risks for these extreme conditions. We will, therefore, provide an overview of the different kind of tests that are required and add some considerations on how the tests can be modified and how the test results are best interpreted for field application.
Effects of CO2/Rock/Formation Brine Parameters on CO2 Injectivity for Sequestration
Authors: Md Yusof Muhammad Aslam , Ibrahim Mohamad Arif , Idress Mazlin , Idris Ahmad Kamal , M Saaid Ismail , Mohd Rodzi Nadhirah , Mohsin Saiful , Azhari Awangku Matali Awangku Alizul
Published: November 2020

CO2 injection into saline aquifer has gained attention as an effective technique to permanently secure the produced anthropogenic gas from high CO2 gas field in South East Asia region. However, problem such as injectivity impairment has been faced by operators and researcher has attributed the interactions between CO2-brine-rock to be the major cause. This research investigated the effect of CO2 displacement schemes, reservoir rock permeability, formation brine type and concentration on CO2 injectivity. CO2 coreflood experiment with detailed characterization of the rock and effluent produced are presented. Various core samples which represent low and high permeability of typical geological storage for sequestration were selected. The core samples were analyzed using X-Ray Fluorescence (XRF), X-Ray Powder Diffraction (XRD) and Field Emission Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (FESEM-EDX). Then it was saturated with synthetic formation brine composed of 6,000 ppm, 30,000 ppm or 50,000 of either Sodium Chloride (NaCl), Potassium (KCl) or Calcium Chloride (CaCl2). Lastly, core samples were injected by either supercritical CO2 (scCO2), CO2-saturated brine and combination of CO2-saturated brine and scCO2 and the pressure drop profile was recorded. Fines were then being separated from the collected effluent for further analysis. FESEM images of the pre- and post-injection core samples were compared to assess physical changes. Results indicated that CO2 injection scheme, flow rate, brine concentration and initial rock permeability are the principal factors that contribute to the porosity and permeability alteration of the core samples. Moreover, FESEM-EDX analysis of the produced fines shows precipitated salt, silica grain and kaolinite were migrated during scCO2 injection. It is suggesting that minerals were dissolved and precipitated, resulting in detachment of silica particles and formation of new secondary minerals, some of which plugged the pore spaces reducing the permeability. In addition, core saturated with CaCl2 brines are the only samples that showed permeability improvement after CO2 flooding experiment.
An Engineering Approach to Optimise Rate of Penetration through Drilling Specific Energy
Authors: Al-Rubaii Mohammed Murif , Gajbhiye Rahul. N , Al-Yami Abdullah , Haq Bashirul , Glatz Guenther , Al-Awami Mohammed
Published: November 2020

Continuous efforts are made in drilling engineering to identify and develop advanced tools and technologies to maximize rate of penetration (ROP). Optimization of ROP has a major impact on both the reduction of the cost in terms of cost per foot and well delivery. Numerous correlations, methods, designs, models, and tools for ROP optimization are available in literature but rarely are applied in drilling operations. This paper introduces a robust methodology aiming to optimize the rate of penetration without inducing any associated wellbore stability problems.

The objective of this paper is to detail the methodology and the effectiveness of the technique introduced. We report performance indicators for a trial well drilled using the novel approach and compare the findings with a conventionally drilled offset well. The drilling parameters for a challenging horizontal hole section were collected and analyzed to evaluate their effect on ROP performance. The drilling parameters selected are from corresponding hole sizes, formation and mud types with respect to the offset well for a consistent comparison. The proposed approach contributed to an enhanced well drilling performance by more than 40% and was instrumental in mitigation of stuck pipe incidents.

In this paper, we introduced and verified a novel technique to maximize the rate of penetration (ROP) by optimizing the drilling parameters (RPM and WOB). As long as the CCA is less than 0.05, the proposed workflow in this study can be used to determine an optimized ROP in conjunction with a minimized DSE yielding ideal RPM and WOB values thereby reducing the cost per foor drilled. Evidence of the efficiency of the proposed procedure is provided by comparing the ROP and DSE measured for a horizontal section drilled employing the technique with data for an offset well drilled in a non-optimized fashion. Compared to the latter case, we reported a 44% improvement in ROP and a 48% reduction in DSE.
Transforming Offshore Oil and Gas Production Platforms into Smart Unmanned Installations
Authors: Tan Jaime HuiChoo , Roberts Brian , Sundararaju Prabakaran , Sintive Christophe , Facheris Laurent , Vanden Bosch Joel , Lehning Virginie , Pegg Mathew
Published: November 2020

Offshore oil and gas production platforms are complex and hazardous process facilities which are usually attended by a permanent human crew to run the daily operations. In recent years, the oil and gas industry has demonstrated strong commitment to change this traditional operations approach and move towards inherently safer philosophy in offshore facilities design and operations, i.e. removing human crew from the facility and operating it remotely from a safe location over extended periods.

This paper aims to demonstrate the readiness of robotics technologies coupled with digitalization technologies in process control and facility automation in transforming offshore oil and gas production platforms into smart unmanned installations. This paper is focused on the application of smart robotics, with highly dexterous capabilities and equipped with multiple sensing instruments, in maintaining an offshore oil and gas production facility in full operation without a permanent human crew, and with planned visits to the platform at 12-week intervals, in a case study. The robots are developed to be remotely operated from an onshore control center and/or may be programmed to function autonomously for routine missions on the offshore facility.
Overcoming the Oil Base Mud Barrier for High Resolution Imaging While Drilling: An Industry First Technology Advancement for Borehole Image Acquisition
Authors: Shrivastava Chandramani , Maeso Carlos , Wibowo Vera , Auchere Jean-Christophe , Amir Irlan
Published: November 2020

New sub-surface challenges are encountered everyday as the industry drills more in complex geological and operational settings; and smarter applications are being made with new and more efficient technologies for real-time solutions. And, one of the remaining frontiers, that of real-time, high-quality, multi-applications borehole images while drilling with oil-base mud (OBM) has been overcome with deployment of multi-sensor, multi-physics measurements providing the highest resolution data. A new feature-based compression technology is developed to transmit the geological feature-rich data in real-time, even with limited telemetry; enabling real-time decision making.

Logging-while-drilling (LWD) imaging in OBM started from low-resolution density images with limited meaningful applications; even ultrasonic imaging introduced lately was not able to consistently unmask the geological information. Industry-first technology advances for borehole image acquisition in OBM were made possible with the deployment of ground-breaking integration of multi-sensor, multi-physics technologies of electromagnetics and ultrasonic on one small sub. Four operational frequencies of electromagnetic measurements are used for resistivity-imaging to cover a wide resistivity range in the sub-surface, whilst ultrasonic images are made at two frequencies to help optimize the imaging for varying standoff and rugosity during drilling. This enables feature identification of subtle variation in texture, structure, sedimentation and diagenesis style; most of the sedimentary structures imaged on the apparent resistivity images made from electromagnetic measurements whilst the drilling-related features manifesting themselves more visibly on ultrasonic images.

Results of this technology are discussed with various examples acquired during the early deployment; examples showing the plethora of information available in real-time enabling drilling optimization to hydro-fracturing decisions. A comparison has also been made with established wireline technology for validation of the LWD images in some of the examples. With more applications being developed to integrate this data, this opens up new avenues for geosciences and drilling solutions while drilling.

This new technology overcomes the OBM barrier for high-resolution imaging while drilling, and coupled with feature-rich data transmission in real-time enables real-time decision making.
Integration of Wireless and Remote Monitoring in Condition Monitoring Systems for Offshore Applications
Authors: Tanabe Satoru , Prasertsintu Thanasin
Published: November 2020

Offshore platforms often contain mission-critical equipment that should be monitored on a real-time basis, but because of the hazardous and hard-to-reach environments they are located in, there are always challenges to the conventional method of using wired sensors and on-site monitoring. The wireless sensor and remote monitoring technologies, introduced in this paper, enables practical condition monitoring to detect early signs of change in machine conditions with limited investment and optimize their overall maintenance program and workflow remotely, for rotating assets on offshore platforms.

The system introduced in this paper is comprised of the wireless sensor and software with remote monitoring capability. The wireless sensor is able to measure key condition monitoring parameters including dynamic vibration data to detect early sign of change in machine condition and support to identify its failure mode as well. Because of its wireless design, initial investment of installation can be minimized. The software interface is designed to provide adequate information to complete asset condition assessment and root cause analysis of the machine failure when it occurs. The software is capable of monitoring assets located on multiple platforms through the network. The data provided by the software can be utilized not only for machine health monitoring but also for reliability assessment, reviewing effectiveness of maintenance at pre & post maintenance or advanced analysis by using the latest technologies, ultimately optimizing maintenance program for those assets observed based on the data captured by the system.

The software is designed to comply with network security requirements of today to establish secure network connections for remote access from an on-shore facility, making condition monitoring data readily accessible, and remotely for analysis by a qualified diagnostic team. This feature allows offshore platform maintenance engineers to plan maintenance tasks effectively. What maintenance tasks need to be performed for which assets, which probable tools and materials are needed will be determined and organized in advance before a maintenance resource is mobilized based on actual data measured the assets. This could potentially reduce the number of trips to remote area where the assets are located such as unmanned platforms, minimize time to be spent by the maintenance resource per visit, optimizing overall maintenance program without compromising asset reliability, quality of maintenance, and safety risk.

This new system with the wireless sensor presented in this paper does not only enhance the visibility of asset condition, but also possible to improve the effectiveness of maintenance tasks and optimize the overall maintenance program with reduced safety & environmental risks for assets on offshore platforms.
Real Time Online Hydrate Monitoring and Prevention in Offshore Fields
Authors: Azman Syahida Husna , Abu Bakar Afdzal Hizamal , Abdullah Nur Hidayah , Jamaluddin Muhamad Nasri
Published: November 2020

Hydrate blockage had caused impeded flow in offshore pipelines and resulted production stoppage and significant economic loss. Hydrate blockages can occur very rapidly especially during winter conditions. The amount of inhibitor used need to be frequently revisited to ensure sufficient inhibition due to temperature change and other affecting parameters. The objective of this study is to provide an online monitoring of hydrate formation for four offshore pipelines to ensure sufficient mono-ethylene glycol (MEG) inhibition. It also provides an integrated operations monitoring that can be accessed anywhere and anytime. The system can provide early warning of hydrate formation to avoid blockage and production disruption.

There are three parts in this study:-Part 1-Hydrate Prediction Model, Part 2-Integration with PETRONAS Integrated Operations platform and Part 3-Hydrate Monitoring and MEG Tracking. In Part 1, fluid composition for each pipeline was used to develop the hydrate curve. The minimum inhibition concentration model was built using mathematical curve fitting at maximum operating pressure under varying temperature. Another computational model was built to determine the MEG injection rates based on various parameters such as water cut, lean MEG concentration and safety margin. The model was then integrated with both real-time and sporadic data and run on predetermined schedule on the Integrated Operations (IO) platform. Part 2 ensures the critical parameters are linked to the hydrate prediction model and provide results such as hydrate operating condition, minimum inhibitor concentration requirement and MEG injection rates. In Part 3, real-time hydrate monitoring has to be readily accessible to everyone via a mobile compatible web interface. Actual MEG concentration vs minimum MEG concentration is analyzed to represent adequacy of current MEG injection rates. Further analysis can be done to predict the MEG recovery plan by tracking MEG inventory.

The online hydrate monitoring is frequently used by offshore operations in their daily meetings. The system assists in advising the amount of MEG injection rates and ensure sufficient inhibition for all of the pipelines. From available trending, operator can optimize the MEG rates based on current operating temperature, pressure, watercut and relevant parameters. This online monitoring is useful to avoid re-occurrence of hydrate blockage in the pipelines and to optimize MEG usage.

There are many hydrate inhibition technologies in existence, but this is the first in the world of its kind which is simple, innovative and inexpensive method to monitor the pipeline from entering hydrate region in real-time, which can be conveniently accessed anytime and anywhere. Not only the system had prevented production loss in millions of dollars, it also saved operating cost of MEG which may cost operations several million dollars.
Augmented Machine Learning Approach of Rate of Penetration Prediction for North Sea Oilfield
Authors: Hong Youngjun , Yoo Jaeyoon , Wang Shinjo , Yoon Sungroh
Published: November 2020

Rate of penetration (ROP) refers to penetration speed in drilling process, which is directly related to drilling cost and time. Therefore, ROP optimization by choosing the best drilling parameters has been an important issue in drilling fields to cut cost and spend less time in drilling. To optimize ROP in an accurate and efficient manner, an accurate ROP prediction should precede. An accurate ROP prediction makes optimizing drilling parameters possible, which leads to cost-effective drilling.

Recently, the development of machine learning brings new insight into various fields including petroleum engineering, where conventional and domain knowledge-based equations were dominant. Particularly, leveraging deep neural networks that are highly capable of representing complex relationship of features has shown promising results in various tasks and fields such as computer vision and language modeling.

In this paper, we present a novel machine learning model for the ROP prediction. We focused on developing a model which is trained with offset well logs data to predict ROP of unseen target wells within the same field. By utilizing the state-of-the-art deep neural networks specialized in sequential data process, we show that the data driven ROP prediction significantly outperforms conventional ROP prediction methods.

In addition, we utilized a stacked generalization ensemble method that integrates several ROP prediction models to produce an optimal ROP prediction model. We also show that our stacked ensemble model can improve prediction performance of a single model.
Ten-Year Pilot Test of Steam and Flue Gas Stimulation for Offshore Heavy Oilfield
Authors: Han Xiaodong , Zhong Liguo , Tang Xiaoxu , Wang Hongyu , Zou Jian , Wang Qiuxia , Liu Hao
Published: November 2020

There is large amount of heavy oil resources whose oil viscosity over 350 mPa·s in Bohai Oilfield and their producing degree and production performance are relative low for lacking of effective exploitation technology. For seeking effective production technology for heavy oil exploitation, the steam and flue gas co-injection technology is proposed and studied. Considering the limited platform space, miniaturized steam and flue gas generator is designed and applied for field test. Besides, integrated matching technologies such as sea water desalinization, heat insulation, anticorrosion are also studied and developed. The south part of NN Oilfield was selected to be the target oilfield and the first thermal pilot area in Bohai Oilfield in 2008. Until now, the pilot in NN Oilfield has lasted for 10 years, nearly 30 well times of stimulation has been conducted and part of these wells has entered the third stimulation cycle. Compared with natural energy production, peak oil production and periodic oil production of thermal production are both greatly improved. With the increase of the stimulation cycle, the gas channeling problem has bad influence on the production performance, and the production rate declines rapidly. Steam flooding might be an effective replaced technology after huff and puff for further enhancing oil recovery of offshore heavy oilfields.