Dual wavefields from distributed acoustic sensing measurements

Geophysics ◽  
2016 ◽  
Vol 81 (6) ◽  
pp. D585-D597 ◽  
Author(s):  
Flavio Poletto ◽  
Daniel Finfer ◽  
Piero Corubolo ◽  
Biancamaria Farina
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Axial Direction ◽  
Borehole Data ◽  
Directional Information ◽  
Native Strain ◽  
Acoustic Sensing ◽  
Wavefield Separation ◽  
Seismic Acquisition ◽  
Distributed Acoustic Sensing

Distributed acoustic sensing (DAS) using fiber optic cables is an emerging seismic acquisition technology for the oil and gas industry, geothermal resource exploration, and underground fluid-storage monitoring. This technology offers the advantage of improving seismic acquisition by enabling massive arrays for monitoring of seismic wavefields at reduced cost with respect to conventional methods. In general, it is accepted that this method provides acoustic signals comparable with conventional seismic data, however, without the multicomponent directional information typical of geophones. We have developed a modified data extraction method and found that, as a result of the dense spatial distribution of recording points along the optic cable, DAS can provide two linked wavefield components in the axial direction, even when using a single 1D cable line. These signal pairs consist of dual components that are related to native strain rate (or strain) and particle acceleration (or velocity) fields at a given recording location. These dual signals are easily usable for wavefield separation purposes simply performing a trace-by-trace combination by appropriate scaling coefficient. The analysis performed with borehole data from linear and helically wound cables demonstrates the effectiveness of polarity recovery and dual-wavefield separation. We show real examples in which the data can be combined to provide separation of up- and downgoing wavefields. The ratio of the dual components provides information on local slowness properties in the formation.

NEW DIRECTIONS IN GEOSCIENCE TECHNOLOGY FOR PETROLEUM EXPLORATION IN THE NEW AGE

1994 ◽  
Vol 34 (1) ◽  
pp. 189
Author(s):  
T. L. Burnett
Keyword(s):  
Oil And Gas ◽  
Regional Scale ◽  
Seismic Energy ◽  
Oil And Gas Industry ◽  
Transport Processes ◽  
Source Rocks ◽  
P Wave ◽  
Petroleum Exploration ◽  
S Wave ◽  
Seismic Acquisition

As economics of the oil and gas industry become more restrictive, the need for new means of improving exploration risks and reducing expenses is becoming more acute. Partnerships between industry and academia are making significant improvements in four general areas: Seismic acquisition, reservoir characterisation, quantitative structural modelling, and geochemical inversion.In marine seismic acquisition the vertical cable concept utilises hydrophones suspended at fixed locations vertically within the water column by buoys. There are numerous advantages of vertical cable technology over conventional 3-D seismic acquisition. In a related methodology, 'Borehole Seismic', seismic energy is passed between wells and valuable information on reservoir geometry, porosity, lithology, and oil saturation is extracted from the P-wave and S-wave data.In association with seismic methods of determining the external geometry and the internal properties of a reservoir, 3-dimensional sedimentation-simulation models, based on physical, hydrologic, erosional and transport processes, are being utilised for stratigraphic analysis. In addition, powerful, 1-D, coupled reaction-transport models are being used to simulate diagenesis processes in reservoir rocks.At the regional scale, the bridging of quantitative structural concepts with seismic interpretation has led to breakthroughs in structural analysis, particularly in complex terrains. Such analyses are becoming more accurate and cost effective when tied to highly advanced, remote-sensing, multi-spectral data acquisition and image processing technology. Emerging technology in petroleum geochemistry, enables geoscientists to infer the character, age, maturity, identity and location of source rocks from crude oil characteristics ('Geochemical Inversion') and to better estimate hydrocarbon-supply volumetrics. This can be invaluable in understanding petroleum systems and in reducing exploration risks and associated expenses.

Visualisation and delineation techniques adopted from other industries to increase productivity of the G&G work in the oil and gas industry

2015 ◽  
Vol 55 (2) ◽  
pp. 475
Author(s):  
Adrien Bisset ◽  
Christopher Han
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Frequency Decomposition ◽  
Knowing That ◽  
Seismic Acquisition ◽  
Decision Making Processes ◽  
Increase Productivity ◽  
Human Interpretation

Given the recent increase of seismic data quality owing to improvements in seismic acquisition and processing, it is surprising to realise that the oil and gas industry is still using standard desktop screens with 256 colour resolution software displays, and for most of the seismic representations, using only three types of colour bars (peak-trough, grey scale or rainbow) for human interpretation, comprehension and decision making processes. Knowing that these displays show 0.000006% of the details captured in 32 bit resolution data, it is a wonder: is the oil and gas industry using the available data to its maximum potential to decrease the risk of drilling dry wells? Astronomy and medical imaging tackled these issues long ago and inspired by them, the oil and gas industry is able to use a 24 bit colour space for representing seismic data in a more appealing way. These innovative seismic data representations are called colour blends and are created using sources such as frequency decomposition products, angle stacks, edge attributes, 4D vintages or any other seismic attributes colour-coded with primary colours. Colour blends have not yet become mainstream due to availability of the tools. The cognitive cybernetics approach allows a more balanced input between data driven processes, interpreter skills and guidance, and has recently been made available for use with colour blends—a breakthrough in interpretation. This extended abstract shows recent advances in these two techniques and how they benefit to the geological and geophysical work based on a case study from the Australian and New Zealand sector.

scholarly journals Accelerometer Sensor Specifications to Predict Hydrocarbon Using Passive Seismic Technique

2016 ◽  
Vol 2016 ◽  
pp. 1-28 ◽  
Author(s):  
M. H. Md Khir ◽  
Atul Kumar ◽  
Wan Ismail Wan Yusoff
Keyword(s):  
Oil And Gas ◽  
Optimal Solution ◽  
Seismic Energy ◽  
Oil And Gas Industry ◽  
Seismic Signal ◽  
Accelerometer Sensor ◽  
Low Frequencies ◽  
Technological Gap ◽  
Passive Seismic ◽  
Seismic Acquisition

The ambient seismic ground noise has been investigated in several surveys worldwide in the last 10 years to verify the correlation between observed seismic energy anomalies at the surface and the presence of hydrocarbon reserves beneath. This is due to the premise that anomalies provide information about the geology and potential presence of hydrocarbon. However a technology gap manifested in nonoptimal detection of seismic signals of interest is observed. This is due to the fact that available sensors are not designed on the basis of passive seismic signal attributes and mainly in terms of amplitude and bandwidth. This is because of that fact that passive seismic acquisition requires greater instrumentation sensitivity, noise immunity, and bandwidth, with active seismic acquisition, where vibratory or impulsive sources were utilized to receive reflections through geophones. Therefore, in the case of passive seismic acquisition, it is necessary to select the best monitoring equipment for its success or failure. Hence, concerning sensors performance, this paper highlights the technological gap and motivates developing dedicated sensors for optimal solution at lower frequencies. Thus, the improved passive seismic recording helps in oil and gas industry to perform better fracture mapping and identify more appropriate stratigraphy at low frequencies.

Distributed Acoustic Sensing System for oil and gas exploration

2019 ◽  
Author(s):  
Tuanwei Xu ◽  
Shengwen Feng ◽  
Kaiheng Yang ◽  
Lilong Ma ◽  
Fang Li
Keyword(s):  
Oil And Gas ◽  
Acoustic Sensing ◽  
Oil And Gas Exploration ◽  
Sensing System ◽  
Distributed Acoustic Sensing

Petroleum Exploration Risk Reduction Using New Geoscience Technology

1996 ◽  
Vol 14 (6) ◽  
pp. 507-534 ◽  
Author(s):  
T. L. Burnett
Keyword(s):  
Oil And Gas ◽  
Regional Scale ◽  
Seismic Energy ◽  
Oil And Gas Industry ◽  
Transport Processes ◽  
Source Rocks ◽  
P Wave ◽  
Petroleum Exploration ◽  
S Wave ◽  
Seismic Acquisition

As economics of the oil and gas industry become more restrictive, the need for new means of improving exploration risks and reducing expenses is becoming more acute. Partnerships between industry and academia are making significant improvements in four general areas: Seismic acquisition, reservoir characterization, quantitative structural modeling, and geochemical inversion. In marine seismic acquisition the vertical cable concept utilizes hydrophones suspended at fixed locations vertically within the water column by buoys. There are numerous advantages of vertical cable technology over conventional 3-D seismic acquisition. In a related methodology, ‘Borehole Seismic,’ seismic energy is passed between wells and valuable information on reservoir geometry, porosity, lithology, and oil saturation is extracted from the P-wave and S-wave data. In association with seismic methods of determining the external geometry and the internal properties of a reservoir, 3-dimensional sedimentation-simulation models, based on physical, hydrologic, erosional and transport processes, are being utilized for stratigraphic analysis. In addition, powerful, 1-D, coupled reaction-transport models are being used to simulate diagenesis processes in reservoir rocks. At the regional scale, the bridging of quantitative structural concepts with seismic interpretation has lead to breakthroughs in structural analysis, particularly in complex terrains. Such analyses are becoming more accurate and cost effective when tied to highly advanced, remote-sensing, multi-spectral data acquisition and image processing technology. Emerging technology in petroleum geochemistry enables geoscientists to infer the character, age, maturity, identity and location of source rocks from crude oil characteristics (‘Geochemical Inversion’) and to better estimate hydrocarbon-supply volumetrics, which can be invaluable in understanding petroleum systems and in reducing exploration risks and associated expenses.

scholarly journals Tailored design of top-tensioned composite risers for deep-water applications using three different approaches

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668427 ◽  
Author(s):  
Chunguang Wang ◽  
Krishnakumar Shankar ◽  
Evgeny V Morozov
Keyword(s):  
Polymer Composites ◽  
Oil And Gas ◽  
Production Capacity ◽  
Oil And Gas Industry ◽  
Axial Direction ◽  
Gas Industry ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Risers with high-grade steel are widely used in offshore oil and gas industry at present. The extreme weight, lower fatigue and corrosion resistance of steel risers significantly limited the exploitation depths and the production capacity. Nowadays, it is acknowledged that using fibre-reinforced polymer composites to manufacture risers can be a better option. The prototypes of composite risers fabricated and tested confirm that fibre-reinforced polymer composites have an obvious advantage over steel risers on weight saving. Three different approaches are developed here to minimise composite risers’ weights: (1) enhancing the riser with only axial-direction and hoop-direction fibre; (2) off-axis reinforcements are included using an iterative approach of manual inspection and selection and (3) employing the optimisation technique of surrogate-assisted evolutionary algorithm. These design approaches have been applied to eight different material combinations to achieve the minimum structural weight by optimising their laminate configurations. The designs are conducted in accordance with the Standards, considering both local load cases and global – functional as well as environmental loads using ANSYS 15.0. The results show that comparing with steel risers, weight savings achieved by different design approaches and material combinations are different.

scholarly journals Deployment recommendation for Distributed Acoustic Sensing at the surface

2020 ◽  
Author(s):  
Pascal Edme ◽  
Patrick Paitz ◽  
Ana Nap ◽  
Francois Martin ◽  
Valentin Metraux ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Reservoir Characterization ◽  
Low Cost ◽  
Broad Band ◽  
Minor Amount ◽  
Acoustic Sensing ◽  
Reflection Seismic ◽  
Order Of Magnitude ◽  
Distributed Acoustic Sensing ◽  
A Minor

<p>Distributed Acoustic Sensing (DAS) is an optical interferometry based ground motion sensing technology which has the potential to revolutionize the field of seismological data acquisition. It offers the possibility to replace very large numbers of cost-intensive conventional point sensors (seismometers or geophones) by interrogating a single low-cost optic-fibre cable. Being unaffected by spatial aliasing, DAS is emerging as a potential next-generation broad-band geo-hazard (e.g. earthquakes, landslides) and reservoir (e.g. geothermal, oil and gas) seismic monitoring tool.</p><p>For borehole applications, with the cable appropriately coupled with the casing, the reliability and benefit of DAS-based VSP acquisition is now widely recognized. At the surface however, for reflection seismic for example, the adequate deployment procedure is less well documented, and experiments are performed with cables sometimes directly deployed on the surface, or sometimes buried quite deep (e.g. one meter) in the ground. Especially for non-permanent monitoring, the trenching effort can be substantial or unaffordable due to logistic or permitting issues. One may wonder if such an effort with its associated cost is actually beneficial.</p><p>We present here the results of a surface-based active seismic experiment conducted in Switzerland in the context of a geothermal reservoir characterization project with “co-located” stretches of cable deployed at different depths. The repeatability of the DAS measurements is quantified and compared to a dense array of conventional multi-component geophones. The study shows that deeply (50 cm) deployed cables offers only marginal data quality improvements compared to very shallow (2 cm) cables. In contrast, the parts of the cable directly laid down at the surface exhibit much larger noise levels and very poor repeatability (approximately one order of magnitude larger NRMS). Our study suggests that only a minor amount of elastic material covering the cable is enough to provide a good coupling and that a modest machine to conveniently perform such a shallow deployment would greatly benefit the growing DAS user community.</p>

Seismic data acquisition—The new millennium

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 54-54 ◽  
Author(s):  
Steve Roche
Keyword(s):  
Data Acquisition ◽  
Seismic Data ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Seismic Acquisition ◽  
Seismic Data Acquisition ◽  
New Millennium

As we enter the new millennium, seismic data acquisition is in an interesting position. Because of overcapacity of seismic acquisition crews related to the downturn in the oil and gas industry, acquisition technology is essentially “frozen” in place. Companies previously active in seismic data acquisition research have limited these activities, or eliminated them. Some advances related to improving the resolution of seismic data through improved acquisition methods are being made, but much more effort is being directed towards improving the efficiency of acquisition.

Buzios: The Biggest Ultra-Deepwater Oilfield to Date

2021 ◽  
Author(s):  
Jose Olavo de Andrada Ignacio de Oliveira ◽  
Pedro Lemos Tavares ◽  
Victor Costa da Silva ◽  
Ivan Noville Rocha Correa Lima ◽  
João Francisco Fleck Heck Britto ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Production Systems ◽  
Oil And Gas Industry ◽  
Project Planning ◽  
Development Plan ◽  
Data Sampling ◽  
Well Test ◽  
Gas Industry ◽  
Field Development ◽  
Seismic Acquisition

Abstract The purpose of this paper is to present a general overview of the Buzios field development plan, projects’ features, and main achievements so far. The development plan adopted a strategy to pursue the balance between acceleration and cash flow optimization, to maximize the return on the huge investment on the block acquisition, and the risk management related to developing several Greenfield Projects simultaneously. To reduce reservoir uncertainties, a comprehensive data acquisition plan was crafted and implemented considering: (a) seismic acquisition, (b) drilling, logging and testing several exploratory and appraisal wells, (c) massive rock and fluid data sampling along the reservoirs, (d) execution of one Extended Well Test and three Early Production Systems. Additionally, the basic design of wells, subsea systems and Floating Production Storage and Offloading ("FPSO") provided flexibility to cover remaining uncertainties yet present in the Transfer of Rights ("ToR") scope, which allows up to 3,150 billion barrels of oil equivalent ("boe") to be produced. This led to technological challenges that needed to be addressed during project planning. We believe that the innovative solutions applied enhanced currently available technologies and delivered an important legacy to the offshore oil and gas industry. Finally, the results obtained so far, with the ramp-up of Buzios projects 1, 2, 3, and 4 provide evidence of the successful adopted strategy and reinforce the decision of deployment of a fifth FPSO under the scope of the ToR contract. The strong results of the asset led to the acquisition of 90% of the Transfer of Rights Surplus ("ToR+"), together with CNOOC Petroleum Brasil Ltda. (5%) and CNODC Brasil Petróleo e Gás Ltda. (5%), which now paves the way for a second wave of development, including the deployment of up to seven additional FPSOs.

Assessment of a Corrosion Under Insulation (CUI) Using DNV RP-F101 Procedure

2009 ◽  
Author(s):  
Afshin Motarjemi
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Axial Direction ◽  
Operating Pressure ◽  
Working Pressure ◽  
Element Analysis ◽  
Gas Industry ◽  
Typical Type ◽  
Pressure Maximum ◽  
Corrosion Under Insulation

Corrosion under insulation is a typical type of localised corrosion in oil and gas industry especially when water penetrates into a damaged thermal insulation/coating. An area of corrosion under insulation (CUI) was observed on the external surface of a pipe on topside of an offshore platform after removing the insulation. Surveys of depth measurements of the corroded area in both longitudinal and circumferential directions (with respect to the pipe axial direction) using a depth micrometer tool were performed and then converted to a river-bottom profile following the procedure of DNV RP-F101 Part A. A best estimate of the failure pressure safe working pressure (maximum operating pressure) of the pipe were calculated. The former was then compared against the finite element analysis (FEA) results which showed good agreement when axial stresses were excluded. The effect of assumptions such as confidence level and inspection sizing accuracy are also discussed.

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