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This paper presents the first successful application of ceramic sand screens offshore Malaysia. Ceramic sand screens were considered as a remedial sand-control method because of their superior durability and resistance compared with metallic sand screens. Shallow-water offshore production began before 1900 and continues to be important. Technology to maximize economic production from shallow-water fields can be adapted from onshore or deepwater technologies. Standalone-sand-screen (SAS) completion, especially in horizontal gas wells with high potential for sand production, typically suffers from premature failure caused by sand erosion resulting from high velocity in the annulus near the heel section.
Horizontal shale well completions require large amounts of sand which present unique challenges to operators during all phases of completion and production. This workshop will take a deep look at the production challenges related to sand in unconventional reservoirs from several different perspectives including varying aspects of the reservoir, the wellbore, and the surface facilities. Operators and service companies will share technologies, experiences, and lessons learned with sand management in shale resource production. Those involved in production operations, reservoir engineering, well maintenance, facilities engineering, artificial lift and completions would benefit from attending.
Hydraulic fracturing or fracking is a well stimulation technique for extracting hydrocarbons from naturally low (extra low) permeable oil and gas reservoirs. In this process water, proppant and chemicals are injected through the wellbore and from the perforation hole into the reservoir. The main goal of this treatment is to create artificial fluid path conduits in the formation and finally increase the permeability (and productivity) of the reservoirs.
One of the important factors which affects the near wellbore fluid pressure drop is the coefficient of discharge (Cd) which is a characteristic of the perforated hole in the wellbore tubular. The coefficient of discharge is defined as the ratio of the measured mass flow to the theoretical mass flow. The Cd depends on many factors and may change with time due to erosion caused by the injected sand, which was pumped into the formation. In this research, we investigated some of the factors that can affect the coefficient of discharge like the erosion of the perforated hole and the backpressure given by the fracture.
For this purpose, we have developed a new high-pressure high-flow rate setup for examining the effect of the following parameters which can alter the coefficient of discharge. More specifically we have investigated the effect of perforation hole size, perforation hole geometry and perforation shape on the Cd value at ambient conditions and with backpressure, before and after sand erosion. To do so, in a first step we have used machined holes with a clearly defined geometry and then compared the results with real perforated holes which were generated using various shaped charge designs. The coefficient of discharge was measured using water or gelled water with different pressure differentials and back-pressures. In our study, we have injected sand slurry for 30 minutes with a constant concentration. The flow rate and pressure drop were also recorded simultaneously during the injection of the sand.
Our results show how the erosion directly affects the Cd value and the subsequent pressure drop near the perforated hole. A clear increase of the Cd magnitude becomes visible only due to a change of the inlet geometry without changing the diameter. Also, the backpressure, which represents real fracking conditions, leads to a significant increase compared to the measurements at ambient outlet pressures.
The measured values before and after the erosion for real perforation holes differ from simple drilled holes. From the recorded results, it also seems that certain perforation shapes or geometries are more effected by erosion than others.
Coates, Shannon (Ecology and Environment, Inc., member of WSP) | Lockhart, Gwen (Ecology and Environment, Inc., member of WSP) | Courbis, Sarah (Advisian, A Member of Worley Group) | Raghukumar, Kaustubha (Integral Consulting, Inc.) | McWilliams, Samuel (Integral Consulting, Inc.) | Jones, Craig (Integral Consulting, Inc.)
This study aimed to produce a pilot spatial model, building upon the existing quantitative Spatial Environmental Assessment Tool (SEAT), to evaluate risks associated with marine hydrokinetic energy (MHK) development within the Pacific Marine Energy Center South Energy Test Site, located off Newport, Oregon. The goal is to establish an approach for integrating natural resource sensitivities with changes in physical conditions caused by wave energy converter arrays to inform planning and impact assessment. To generate the model inputs, a benthic substrate proxy within the project area was defined as a "sensitive resource" input (
The results from acoustic logs can shed light on two issues geologists typically address: erosion and uplift estimation, and organic richness/source-rock potential. The amount of erosion that has occurred in a region that has been uplifted can be estimated from the degree of shale compaction measured by acoustic travel time. This technique assumes that shale compaction is irreversible and that the shale retains the degree of compaction it gained at its maximum burial depth. Acoustic slowness, used alone or in conjunction with formation resistivity, can provide qualitative indications and quantitative determination of source-rock potential (when calibrated to laboratory data). The identification of potential petroleum-source rocks and characterizing the thermal maturity of these rocks is important for assessing petroleum potential (risking) and for basin modeling.
Conventional well completions in soft formations (the compressive strength is less than 1,000 psi) commonly produce formation sand or fines with fluids. These formations are usually geologically young (Tertiary age) and shallow, and they have little or no natural cementation. Sand production is unwanted because it can plug wells, erode equipment, and reduce well productivity. It also has no economic value. Nonetheless, formation sand production from wells is dealt with daily on a global basis.
The slotted liner or screen is the mechanical device that contains the gravel-pack sand in an annular ring between it and the casing wall or open hole. Figure 1 shows a schematic of the function of a slotted liner or screen in an openhole gravel pack. Slotted liners are made from tubulars by saw-cutting slot configurations, as shown in Figure 1. Slot widths are often referred to in terms of gauge. Slot or screen gauge is simply the width of the opening in inches multiplied by 1,000.
The primary objectives of perforating a lengthy cased-and-cemented wellbore section for fracture stimulation are to enable extensive communication with the reservoir and control the allocation of fluid and proppant into multiple intervals as efficiently as possible during fracturing treatments. Simultaneously treating multiple intervals reduces the number of fracture stages required, thus reducing treatment cost. One way to control the allocation is to use limited-entry perforating. Execution and optimization of limited-entry perforating requires awareness of the factors that can affect performance. This paper presents a case study of plug-and-perforate horizontal-well treatments in an unconventional shale play in which various diagnostic methods were used to better understand these factors.
Within the case study, three types of perforation-evaluation diagnostics were implemented: injection step-down tests and pressure analysis of the fracturing treatments, video-based perforation imaging, and distributed acoustic sensing (DAS).
Injection step-down tests indicated that all perforations were initially accepting fluid. Surface-pressure analysis of the main fracturing treatments indicated that in certain cases, several perforations were not accepting fluid and proppant (slurry) by the end of the job.
Video-based imaging indicated that a large majority of perforations showed unambiguous evidence of significant proppant entry. Evaluation of the erosion patterns on the perforations showed a positional bias where for a given fracture stage, perforations in clusters nearest the heel of the well were more eroded than perforations in clusters nearest the toe of the well.
DAS analysis showed a positional bias, allocating more slurry volume to clusters nearest the heel of the well. However, DAS analysis also showed that changing the number of perforations in a cluster had a larger effect than the positional bias.
The results of the case study indicated that a staggered perforation design using more gradual changes among clusters would lead to a more balanced treatment. This scenario was evaluated along with a job design featuring high excess perforation friction and an equal number of perforations in each cluster. Fracture-simulation runs indicated that both tactics are likely to improve slurry allocation.
Abrashov, V. N. (Sibneftegas JSC) | Zhonin, V. V. (RN-BashNIPIneft LLC) | Imashev, R. N. (RN-BashNIPIneft LLC) | Litvinenko, K. V. (RN-BashNIPIneft LLC) | Mikhaylov, A. G. (RN-BashNIPIneft LLC) | Nasyrova, M. I. (RN-BashNIPIneft LLC) | Skorobogach, M. A. (Sibneftegas JSC) | Faritov, A. T. (Akrus-M SPE LLC)
The PDF file of this paper is in Russian.
The article is devoted to development of a methodology for studying the phenomenon of solid particles erosion of metals during interaction of a target material with abrasive particles in a gas stream. Gas-abrasive wear of gas field equipment elements as a result of mineral impurities removal from the formation is a common problem in the oil and gas industry, which is the cause of industrial accidents, outage, production losses, and expensive repair procedures due to premature failure of most significant elements of field equipment. While developing a comprehensive erosion model, it is very important to determine the area of applicability and empirical data corresponding to the selected model. The current paper demonstrates a methodology for performance of laboratory sand blasting tests of materials, representing a pair ‘abrasive particles – steel’, in order to determine different steels’ gas-abrasive wear resistance ability, as well as to identify the most aggressive conditions from the point of view of erosion phenomenon. Sand blasting tests of materials were performed with the use of a special laboratory equipment installation, consisting mainly of an ejector tube for directing the atmospheric air flow containing mineral impurities, which is installed right in front of the rigidly fixed steel sample. The main goal of the experiments was to determine the dependences of the target material mass loss on the abrasive particles velocity magnitudes, the size of the particles, impact angle, and particles parcel mass. The design of the fastening of the target made it possible to install the sample at arbitrary angles to the air flow direction. Quartz sand was used as the material of abrasive particles. To capture the particle velocity, high-speed video shooting technology was used. According to the obtained data representing a range of dependences, basic empirical parameters such as a material constant and a velocity exponent were identified, and considered to be necessary for further mathematical modeling. Experimental data obtained from the laboratory sand blasting tests will be used as input data for further numerical modelling of gas field equipment elements based on a new methodology for predicting of erosion rate of a range of field equipment and gas gathering pipeline system elements.
В статье рассмотрена разработка методики исследования эрозии металлических материалов при взаимодействии с абразивными частицами в потоке газа. Газоабразивный износ элементов промыслового оборудования в результате выноса механических примесей из пласта – распространенная проблема в нефте- и газодобывающей промышленности, которая является причиной аварийных ситуаций, простоя оборудования, производственных потерь, дорогостоящих ремонтных операций вследствие преждевременного выхода из строя важнейших узлов и элементов промыслового оборудования и ухудшения продуктивных характеристик скважин. При разработке комплексной модели эрозии важной задачей является определение области применимости и соответствующих выбранной модели эмпирических данных. Предложена методология проведения лабораторных испытаний пар материалов типа абразив - сталь с целью установления степени стойкости ряда сталей к газоабразивному износу, а также выявления наиболее агрессивных условий с точки зрения эрозии. Испытания пар материалов проводилось на специальной лабораторной установке, основной частью которой являлось сопло, направляющее поток воздуха с примесями и установленное напротив жестко закрепленного стального образца. Эксперимент заключался в определении зависимостей потери массы испытываемого материала от скорости полета частиц абразива, их размера, концентрации, угла атаки и массы. Конструкция крепления образца позволяла устанавливать образец под произвольными углами к направлению потока воздуха с примесями. В качестве абразива использовался кварцевый песок разного фракционного состава. Для фиксации скорости частиц использовалась технология скоростной видеосъемки. Исходя из полученных зависимостей, в результате эксперимента получены основные эмпирические параметры, необходимые для дальнейшего математического моделирования: материальная константа и экспонента скорости. Экспериментальные данные, полученные в результате лабораторных испытаний, планируется использовать в качестве входных параметров при дальнейшей разработке имитационных моделей элементов промыслового оборудования на основе новой методики прогнозирования скорости газоабразивного износа элементов на примере фонтанной арматуры, обвязки скважин и газосборной системы.
This paper documents the development, qualification and field test deployment of an electrically powered and wired drill pipe system for use by operators, drillers and service companies in oil & gas drilling operations. Deployment of the technology has the potential for users to power downhole tools from surface and thus reduce or remove downhole batteries / turbines. High-speed bi-directional telemetry over the wired drill pipe can improve realtime communications and downhole measurement quality, while enabling high frequency, surface and downhole data sharing / integration.
The development of the system is centered around: a braided conductor and an insulating material a robust field replaceable pipe connector system transceivers optimized for the transmission characteristics of the system
a braided conductor and an insulating material
a robust field replaceable pipe connector system
transceivers optimized for the transmission characteristics of the system
The novelty of the new drill pipe design is the ability to supply downhole tools with power in addition to bi-directional high-speed data communication telemetry from surface over the same braided and insulated conductor, manufactured into the ID profile of the drillstring. Due to power regulation at surface and matched transceivers, the need for in-string communications repeaters is avoided. In addition, special attention has been paid to the design, robustness and field maintainability of the connector system at each end of the drill pipe.
Qualification of the system in a laboratory environment applied downhole drilling conditions using simulators, highly accelerated life tests ("HALT"), and physical testing on discrete samples, joints and short strings of drill pipe. Transceiver performance, connector make/break cycles and testing of the conductor and insulating layer under tension, bending, torque, pressure, temperature and erosion were all performed. Parallel "real life" runs on testing and commercial drilling rig operations have yielded encouraging early results to validate the qualification laboratory testing. Minimal damage was observed during handling and downhole use on several drilling rigs, indicating that the system has the potential to be handled as regular drillpipe and can be simply integrated into rig operations.
Several iterations in design and testing of the braid and insulating material have proven the viability of new manufacturing techniques and given valuable insight as to the ability of the design to withstand normal drilling conditions of flow, torque, tension, pressure, temperature etc. gained through commercial drilling rig testing. System trials on rig operations have shown that stable downhole power can be delivered whilst communicating with a minimum bit rate of 56Kbit/sec during drilling. A top drive slip-ring assembly at surface and a crossover to a service company BHA downhole have been developed and were used for the drilling trials.