Onshore Testing Research Articles

Holes of hope and uncertainty – test wells as a site of potential, exploration and the verdict on Greenland’s oil development in the 1970s and 1990s

ABSTRACT This study examines the history of oil development in Greenland with a focus on test wells – the physical sites where and when the future of Arctic oil as an energy source was established and eventually abandoned. The processes surrounding the establishment of the first offshore test wells in the 1970s and the first onshore test well in the 1990s illustrate different contexts of oil development, as well as the similarities between the different phases. Looking at these periods through the lens of infrastructural delay, an umbrella concept that unites anthropological analyses of unfinished, delayed or unrealised infrastructure, this study shows how common themes of potential, exploration and verdict emerge that accompanied the establishment of physical test wells. Based on a thematic analysis of historical scientific and policy reports as well as Greenlandic media accounts, this study brings together a top-down and a local perspective on the construction of test wells in the 1970s and 1990s. This study advances research on the history of Arctic oil development by identifying the different phases of its delay that accompanied the creation of its physical infrastructure, each of which generated different social processes of hope and despair, and which also lay the foundation for future perspectives on the use of Greenland’s subsurface beyond oil.

Experimental Evaluation of the Motion-Induced Effects for Turbulent Fluctuations Measurement on Floating Lidar Systems

This study examines how motion influences turbulent velocity fluctuations utilizing measurements obtained from a wind lidar profiler. Onshore tests were performed using a WindCube v2.1 lidar, which was mobile and mounted on a hexapod to simulate buoy motion. Additionally, a fixed WindCube v2.1 lidar was used as a reference during these tests. To assess the motion-induced effects on velocity fluctuations measured by floating lidar systems, the root-mean-square error (RMSE) of velocity fluctuations obtained from the fixed and mobile lidars was calculated. A comprehensive wind dataset spanning 22.5 h was analyzed, with a focus on regular motions involving single-axis rotations and combinations of rotations around multiple axes. The investigation of single-axis rotations revealed that the primary influencing factor on the results was the alignment between the tilt direction of the mobile lidar and the wind direction. The highest RMSE values occurred when the tilt of the mobile lidar leans in the wind direction, resulting in pitch motion, whereas the lowest RMSE values were observed when the tilt of the mobile lidar leans perpendicular to the wind direction, resulting in roll motion. Moreover, the addition of motion around extra axes of rotation was found to increase RMSE.

Using discrete-element method hindcasting of screw pile performance for practical design

Screw piles have been used to support a variety of structures due to their ease of installation and high axial capacity. Recently, screw piles have been proposed as an alternative foundation solution for offshore renewable structures due to their quiet or silent installation. Due to their variable geometry, design and prediction of installation requirements and its effect on in-service capacity may be challenging. In this research study, the discrete-element method (DEM) is used to numerically recreate a series of onshore field tests. The aim of the study is to investigate the ability of DEM to be used as a practical design tool for the design and deployment of screw piles. In this case study, the effect of the geometric helix pitch on the installation torque and tensile capacity of screw piles installed into sand is investigated. DEM results show that the geometric pitch of a screw pile appears to have little effect on the installation torque. The results show that DEM has the potential to be used as a practical design procedure for complex foundation installation where the simulation needs to capture installation effects.

Automated Drilling-Fluids-Measurement Technique Improves Fluid Control, Quality

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 204041, “Automatic Drilling-Fluids Monitoring,” by Knut Taugbøl, SPE, Equinor, and Bengt Sola and Matthew Forshaw, SPE, Baker Hughes, et al., prepared for the 2021 SPE/IADC International Drilling Conference and Exhibition, originally scheduled to be held in Stavanger, 9–11 March. The paper has not been peer reviewed. The complete paper presents new units for automatic drilling-fluids measurements with emphasis on offshore drilling applications. The surveillance of fluid properties and the use of data in an onshore operations center is discussed. The authors present experiences from use of these data in enabling real-time hydraulic measurements and models for automatic drilling control and explain how these advances can improve safety in drilling operations and drilling efficiency. Introduction An operator has worked with different suppliers for several years to find and develop technology for automatic measurements of drilling-fluid properties. In the described study, methods for measuring parameters such as viscosity, fluid loss control, pH, electrical stability, particle-size distribution, and cuttings morphology and mineralogy were all fitted into a flow loop in an onshore test center. These tests, however, were all performed with prototype equipment. Since then, work has continued to optimize equipment for offshore installations, made for operating in harsh environments and requiring limited maintenance to provide continuous and reliable data quality. The fluid-measuring technique presented in this paper is based on rheology measurement through a pipe rheometer and density measurements through a Coriolis meter. This rheometer measures at ambient temperature. Dual DP is the terminology that refers to pressure measurements between two differential pressure sensors. The dual-DP pipe rheometer is set up with high-accuracy pressure transducers to measure pressure loss inside the straight section of the pipe rheometer. By varying the flow rate through pipes of different dimensions, a rheology profile at varying shear rates can be calculated. Field Implementation Installation of a unit begins with a rig survey conducted in concert with the drilling contractor to find the best location and sampling point. Fluid normally is taken from the charge manifold for the mud pumps, ensuring measurement of the fluid going into the well. The first installation in the North Sea of an automatic fluid-monitoring (AFM) unit was in 2017. This unit is still operational, sending data to an onshore support center. Fig. 1 shows such a unit installed offshore. The AFM unit has only one movable part, the monopump supplying drilling fluid through the unit. Once the dual-DP rheometer was factory-acceptance-tested in the yard, it was sent offshore to be commissioned and verified on a fixed installation in the North Sea. The related data presented in the complete paper were acquired in the field while drilling the 355-m, 8½-in. section with 1.35-SG low-equivalent-circulating-density oil-based drilling fluid, with drilling conducted at approximately 4000 m measured depth. The mud engineer onboard was requested to perform rheology checks on a viscometer at equal ambient temperature to the AFM so that the results could be compared; the AFM also measures rheology at ambient temperature.

MV-22B Short Takeoff and Minimum Run-On Landing Tests Aboard Nimitz-Class Ships

Tiltrotor aircraft ship suitability and envelope expansion testing aboard a U.S. Navy aircraft carrier is discussed. The purpose was to validate and expand day/night vertical launch and recovery wind envelopes, and the development of short takeoff and minimum run-on landing wind envelopes. The preparation phase incorporated a six-degree-of-freedom motion flight simulator to evaluate flight dynamics prior to on-shore testing using V-22 developmental and production aircraft. The short takeoff and minimum run-on landing testing totaled 12.3 flight hours with 33 takeoffs and 32 landings. The gross weights ranged from 51,000 to 57,000 lb with of relative wind from 0 to 45 kt. The test pilots provided assessments of handling and flying qualities throughout the maneuvers using the deck interface pilot effort scale. Predictability tests were required to determine the pilot’s ability to land within the defined touchdown zone and speeds for safely stopping within the braking zone. The results show the integrated nature of shipboard flight testing and the process of combining pilot workload ratings, control strategies, and aerodynamic analyses to field a needed capability.

A review on the behavior of helical piles as a potential offshore foundation system

Helical piles are used mainly to resist tension forces generated by uplift and overturning moments of various structures, therefore they have been suggested as a potential alternative to driven piles as offshore pile because they provide a large uplift capacity due to the anchor effect of the helix. To date no standards are available for the assessment of the use of helical piles in the offshore environment. State-of-the art installation and uplift capacity assessment is based on field onshore tests on small helical piles. The purpose of this review is to critically evaluate the current knowledge on helical piles considering uplift capacity, cyclic load, installation torque models and the parameters affecting the installation torque, to understand whether they can be considered for potential offshore applications. The paper could be of valuable interest for engineers and contractors involved in the offshore installation of piles.

The second natural gas hydrate production test in the South China Sea

Clayey silt reservoirs bearing natural gas hydrates (NGH) are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit. They are proved to be exploitable by the first NGH production test conducted in the South China Sea in 2017. Based on the understanding of the first production test, the China Geological Survey determined the optimal target NGH reservoirs for production test and conducted a detailed assessment, numerical and experimental simulation, and onshore testing of the reservoirs. After that, it conducted the second offshore NGH production test in 1225 m deep Shenhu Area, South China Sea (also referred to as the second production test) from October 2019 to April 2020. During the second production test, a series of technical challenges of drilling horizontal wells in shallow soft strata in deep sea were met, including wellhead stability, directional drilling of a horizontal well, reservoir stimulation and sand control, and accurate depressurization. As a result, 30 days of continuous gas production was achieved, with a cumulative gas production of 86.14 ×10⁴ m³. Thus, the average daily gas production is 2.87 ×10⁴ m³, which is 5.57 times as much as that obtained in the first production test. Therefore, both the cumulative gas production and the daily gas production were highly improved compared to the first production test. As indicated by the monitoring results of the second production test, there was no anomaly in methane content in the seafloor, seawater, and atmosphere throughout the whole production test. This successful production test further indicates that safe and effective NGH exploitation is feasible in clayey silt NGH reservoirs. The industrialization of hydrates consists of five stages in general, namely theoretical research and simulation experiments, exploratory production test, experimental production test, productive production test, and commercial production. The second production test serves as an important step from the exploratory production test to experimental production test.

Design and test of a 600-kW horizontal-axis tidal current turbine

Tidal current energy is a promising renewable energy resource. Full scale tidal current turbines (TCT) have been deployed all over the world. To verify the design methods of large TCTs with high reliability and efficiency, a 600-kW tidal current turbine was designed and tested in this study. This turbine consisted of a two-blade rotor, a low speed ratio gearbox and a medium speed generator. The turbine was grid-connected through a full-rated converter, and its speed was controlled to capture the maximum power. First, to reach high turbine performance, system design details and maximum power point tracking (MPPT) control strategy were considered. Then, the 600-kW turbine was manufactured, and an onshore test was carried out to test power transmission and control performance. The power performance of the blades and control system were further tested in the sea trial carried out in Zhoushan. Good agreement was obtained between theoretical analyses and test results. Finally, to ascertain causes for observed power fluctuations, the power spectral density (PSD) was analyzed; the results indicated that power fluctuations may be due to stream shear.

Field Validation of Demanded Power Point Tracking Control Algorithm for Medium-Capacity Wind Turbine

In this paper, the previously proposed demanded power point tracking (DPPT) control is applied to a medium-capacity wind turbine. Based on the results of our previous studies, the control algorithm has modified to be advantageous for wind farm control and load reduction of individual wind turbines. The target turbine is a medium-capacity turbine with a rated power of 100 kW and uses direct drive-train and integrated pitch control via hydraulic pressure. Experiments were carried out for each of 100%, 30%, and 20% of the rated power with natural wind conditions at an onshore test bed in Jeju Island in South Korea. The performance data was measured at a sampling frequency of 2 Hz by changing the power command. Test results show that the power is limited by the control method presented in accordance with the power command. In addition, it is confirmed that the turbine operates similarly to the in-house simulation model.

A testing platform for subsea power cable deployment

The failure of subsea cables has been predominantly attributed to third party activities and cable field joints. Field joints may be unavoidable due to joining of insufficient factory-made cable lengths, cable repair, or when the cable installation process has to be abandoned due to rough weather or other unplanned events. Failures within the jointing location reveal that current quality testing of these joints may be inadequate. The failure mode in these joints is mainly a result of seawater ingress at the field joint. Current design practices for subsea cable field joints recommend offshore simulations/trials to demonstrate the long term performance of the joint under the expected mechanical loads during cable installation to demonstrate whether the planned field joining practice is satisfactory. Nevertheless, offshore simulations are costly, and therefore a set of standardized onshore testing schemes would be advantageous alternative. This paper presents an onshore testing scheme for subsea power cable deployment. The proposed testing arrangement can be employed to verify the design of the offshore field joint and to prove the functionality of the field joint under the installation loads.

Horizontal Pendulum Performance Analysis with Multilevel Model Plate on Ocean Wave Electric Power Plant (PLTGL)

- With the times and the industry, the energy sources such as fossil fuels dwindling. It encourages all parties to be more advanced and developed by creating solutions to renewable energy generation with the latest innovations, one of which is the sea wave power plant - pendulum system. Ponton who uses pendulum system is one tool used to convert from ocean wave energy into electrical energy. In this study using the test conditions without using ballast onshore and off-shore testing with the ballasts. Obtained from testing the many rounds that can be generated pendulum pie plate thickness and the angle of the pontoon. To test the largest on-shore power obtained on the test using arc angle 30 °, 3 mm thick, the angle of 60o power produced 0036 watts. For testing offshore in the ballasts 12 cm, 15 cm, 17.5 cm, the largest power generated at 15 cm ballasts with 0041 watts power on pie, thick, and a tilt angle equal to the on-shore testing. Number of rounds with time, the on-shore testing that produces the greatest value in the segment with an angle of 30 °, a thickness of 3 mm the angle of 60o value obtained 0.938 rad / s. In the off-shore pengjuain is greatest in the ballasts 15 with 0847 rad / s.

Spoiled darkness? Sense of place and annoyance over obstruction lights from the world’s largest wind turbine test centre in Denmark

The relation between wind power development and local communities has received considerable attention in literature and practice. Relatively few studies, however, have provided evidence about how local citizens perceive enduring environmental impacts such as aviation obstruction lights installed on wind turbines or on wind farm light masts. Evidence regarding people’s perceived annoyance over obstruction lights is of increasing importance as wind turbines become taller, thus potentially affecting more people in the future. The paper conducts individual web-based surveys and interviews with local residents around the world’s largest onshore test site for tall wind turbines in Denmark – the national test site in the rural area of Østerild. The aim is to explore the nature and extent of perceived annoyance over aviation obstruction lights from the test site and the efficiency of different coping strategies. In particular, the discussion focuses on the perceived annoyance in relation to the perceived changes in sense of place, hereunder the loss of the area’s unique night darkness. We argue that perceived annoyance can only be mitigated through coping strategies to a limited extent, as a) perceived effects on sense of place are distinctive in shaping annoyance, and b) an internalisation of planning-related inequities persists.

Offshore Measurement System for Wave Power—Using Current Loop Feedback

This paper presents the design and testing of a measurement system for wave power generators. The work is part of a project to build a robust and cheap measurement system for offshore monitoring of wave power farms. Due to the harsh offshore environment, low accessibility and high cost for installation and maintenance, it is of key importance to minimize power consumption, complexity and cost of each measurement unit. For the first prototype, the objective was to measure voltage, current and translator position inside the linear wave power generator. For this, two printed circuit boards (PCBs) were developed, using a two wire current loop transmitter setup. They were tested separately and in a three phase setup inside a wave power generator during onshore tests. To ensure stability, speed and accuracy in the signal transfer, the PCBs were tested for linearity, frequency response and step response. In addition, power consumption was measured, for operational time evaluation. Results show good agreement between expected and measured performance, with an input range of ±1560 V and ±420 A for alternating current measurements and a bandwidth of 10 kHz and 7 kHz, for voltage and current measurements, respectively. The power consumption was measured to 0.5 W for each measurement unit, at 24 V feed.

Simulated in-line deployment of offshore rigid field joint – A testing concept

Failure of submarine power cables have been shown to be attributed to cable field joints in 18% of cases. This high failure rate at the joining location indicates that the current acceptance testing of these joints is inadequate. The failure mode of these joints is believed to be entirely due to water ingress at the field joint location. Submarine cable field joints are required during installation due to cable repair, joining of insufficient manufactured cable lengths or when the lay process has to be abandoned due to the sea state.Current design guidance for cable field joints suggests sea trails to determine if the proposed field joining technique is acceptable. Sea trails, however, are often prohibitively expensive, such that a set of standardised onshore testing regimes which improves both the reliability and affordability of these tests would be advantageous.This paper outlines a recent cable field joint onshore testing regime to ensure the cable joint integrity during the laying process as well as serviceability in operational life. The paper outlines a process for simulation of the calculated cable laying tension and bend radius with a set of physical tests developed for mechanical and water ingress protection.

An ROV operated undersea hydraulic hose repair coupling

A hydraulic hose repair system is presented that was developed for use at the Deepwater Horizon accident site. The system can be deployed with a single ROV with two controllable arms. One arm holds the device and the other arm pushes a severed hose into the device. Hydraulic pressure is applied from the ROV to the device and a hydraulic coupling within the device is crimped into one end of the hose. The second hose end to be spliced to the first is pushed into the other side of the device and the second half of the coupling is crimped onto the second hose end. The device itself is left in place as part of the splice. The design, on-shore testing, and fabrication of multiple devices ready to deploy at the accident site took on the order of a week to complete. They stand ready to be deployed in the case of another deep-water accident.

TOPFARM: Multi‐fidelity optimization of wind farms

A wind farm layout optimization framework based on a multi-fidelity optimization approach is applied to the offshore test case of Middelgrunden, Denmark as well as to the onshore test case of Stag Holt – Coldham wind farm, UK. While aesthetic considerations have heavily influenced the famous curved design of the Middelgrunden wind farm, this work focuses on demonstrating a method that optimizes the profit of wind farms over their lifetime based on a balance of the energy production income, the electrical grid costs, the foundations cost, and the cost of wake turbulence induced fatigue degradation of different wind turbine components. A multi-fidelity concept is adapted, which uses cost function models of increasing complexity (and decreasing speed) to accelerate the convergence to an optimum solution. In the EU-FP6 TOPFARM project, three levels of complexity are considered. The first level uses a simple stationary wind farm wake model to estimate the Annual Energy Production (AEP), a foundations cost model depending on the water depth and an electrical grid cost function dictated by cable length. The second level calculates the AEP and adds a wake-induced fatigue degradation cost function on the basis of the interpolation in a database of simulations performed for various wind speeds and wake setups with the aero-elastic code HAWC2 and the dynamic wake meandering model. The third level, not considered in this present paper, includes directly the HAWC2 and the dynamic wake meandering model in the optimization loop in order to estimate both the fatigue costs and the AEP. The novelty of this work is the implementation of the multi-fidelity approach in the context of wind farm optimization, the inclusion of the fatigue degradation costs in the optimization framework, and its application on the optimal performance as seen through an economical perspective. Copyright © 2013 John Wiley & Sons, Ltd.

Criticality Testing of Drilling-Fluid Solids-Control Equipment

Summary Correct selection and use of solids-control equipment are essential in not only maintaining drilling fluid at its desired properties but also in avoiding the generation of unnecessary waste streams during drilling. Since the early 1930s, the shale shaker has been the dominant device for primary-solids removal. Additional equipment (e.g., desilters, desanders, and centrifuges) was often used in the past to maintain proper solids control, but experience in recent years has demonstrated that, although dependent on correct operational procedures, several types of shale shakers have sufficient performance to act as the sole solids-control devices without the use of desanders and desilters. Despite often being the only measure for solids removal, the selection of shale shakers, the screening, and the establishment of operational procedures are often based on biased information (Dahl et al. 2006). In addition, it has been recognized that methods and criteria for the verification of shale shakers have not been sufficiently qualified and standardized. To address this, a multidisciplinary verification test of various solids-control concepts has been conducted. The objective of the test has been to verify equipment performance in a standardized, onshore test facility related to Oil-mist and vapor emissionVentilation (to obtain a satisfactory working environment)Flow-handling capacity with various drilling fluidsLeakage rate (i.e., the volume of fluid bypassing the filtration screen)Lost-circulation-material featureNoise and vibration levelMaintenance and equipment robustnessFeature for running lost-circulation-material reclamation The tests were all planned and run in close cooperation with the equipment suppliers to ensure test-objective alignment. Several findings were made throughout the test period that provided vital information for design improvements and increased the industry's competence with respect to solids control.

Application of high-speed fiber bragg grating sensing system for safety monitoring of modern ships

Structural health monitoring (SHM) can be understood as the integration of sensing intelligence and possibly also actuation devices to allow the structure loading and damaging conditions to be recorded, analyzed, localized and predicated. SHM sensing requirements are very well suited for fiber optic technology. The fiber Bragg grating (FBG) sensor is a promising sensor of SHM for many applications because of its good optical properties, small size, low insertion loss, antiRF, anti-electromagnetic interference, breakdown voltage, radiation-resistant, light weight, small and large signal bandwidth. There also are reports of the application of FBG sensors for SHM of large industrial and civil works such as dams, bridges [1−2] , aero plane [3] , and tunnels [4,5] . The development of ship’s SHM takes advantage of multidisciplinary work that is being done, and most of the applications reported are about ship hull monitoring systems [6,7] . Previous studies mostly focus on the measurement of static stress [8] . For a modern ship, the thruster is a key part of the propulsion machinery, and the stability of its related equipments has a great influence on the propulsion efficiency of the ship. Electric resistance strain sensors are difficult to be used for the stress measurement for the thruster because of the electromagnetic disturbance and other complicated environment. Low-speed FBG sensors cannot meet the requirements due to the propulsion machinery’s 100 Hz arising vibration frequency. The high-speed FBG sensing system can be used to measure dynamic stress and achieve the goal of safety monitoring in advanced ships. In this letter, the application of a high-speed FBG sensing system for SHM of modern ships is proposed. We apply this sensing system to give on-site tests to an advanced ship. Strain distribution of the bases and supporting frames of its large turbine thrusters are measured both onshore and in the sea when it runs at different work conditions. The maximum natural frequency of this measured structure is 335 Hz. To test all the monitoring points synchronously, an 8-channel senor system is applied, and the data acquisition frequency was 1000 Hz. Most monitoring points are set with single-line sensors for unilateral stress, and the others are set with triple directions sensors to measure shear stress. Temperature compensation is taken with additional FBGs to eliminate the effect of cross-sensitivity between temperature and strain on FBG sensors. As for every single monitoring point, the max and average stress-gas turbine power factor (GTPF): N/Ne curves are analyzed. Then we synthesize all the results from three-time onshore tests and acquire the static stress-GTPF curves. Results from the test at sea are discussed together, thus we can accomplish completely prediction of the dynamic stress-GTPF curve when we did not obtain dynamic data in every work condition because of some objective reason. We examine the vibration amplitude of the wave length of signal light from each specific monitoring point under the same work condition for all tests and find it barely affected by the environment factors, unlike the absolute wave length. Those experimental results are accordant with mechanical theories, and the final reports have obtained clients’ approval. FBGs are periodic alterations in the index of refraction of the fiber core, and only the specified wavelength (Bragg wavelength) related to its grating period is reflected for an input light wave form a broadband source.

メタンハイドレート資源開発研究コンソーシアム・生産手法開発分野の研究について

The role of the Research Group for Production Method and Modeling is to develop practical natural gas production methods from methane hydrate resources off-shore Japan. While natural gas produces from methane hydrate resources, unique behavior occurs in the methane hydrate sediment due to the physical properties of methane hydrate, and it does not observe in the conventional gas production. Four research subjects have been settled and carried out in Phase 1.In the subject of “Characterization of the sediment”, in-situ analysis system of physical properties of methane hydrate sediment has been developed, and various properties of fundamental properties, frame structures and mechanical properties of natural core sample were analyzed. Finally, methane hydrate reservoir parameters have been clarified.In the subject of “Clarification of the dissociation behavior of the sediment”, to establish the models for behavior over the entire sediment from the pore scale at the methane hydrate sediment dissociation, the analysis of the mass and the heat transfer phenomenon at the dissociation were executed. And the specific behavior during production process such as ice formation, methane hydrate re-generation, changes in mechanical properties are modeled. These models were introduced to the production simulator.In the subject of “Development of the production simulator”, various calculation modules such as a dissociation rate, a consolidation property and a permeability property, were developed. Exclusive production simulator (MH21-HYDRES) and geomechanical simulator (COTHMA) have been developed. Also, the performance of MH21-HYDRES was confirmed through the international bench mark test.In the subject of “Development of the dissociation and the recovery method”, various dissociation methods were tested to establish an efficient, economical production method. Finally, depressurization method was proposed as an efficient method, and it was verified in the on-shore production test at the Mackenzie Delta/Canada.In this review, the research achievements of the Research Group for Production Method and Modeling were introduced briefly.

Onshore testing of produced water by electroflocculation

Onshore testing of produced water by electroflocculation