TROBRIAND BASIN EXPLORATION, PAPUA NEW GUINEA

1976 ◽  
Vol 16 (1) ◽  
pp. 81 ◽  
Author(s):  
K.T. Tjhin
Keyword(s):  
Seismic Data ◽  
Regional Studies ◽  
Aeromagnetic Survey ◽  
Tectonic Plates ◽  
Seismic Surveys ◽  
Irian Jaya ◽  
Petroleum Generation ◽  
Exploratory Wells ◽  
Marine Seismic ◽  
East West

Regional studies suggested that the Solomon Sea would be underlain by upper Tertiary sediments inluding possible Miocene reef carbonates similar to those found in the Gulf of Papua and Irian Jaya. As the Trobriand area of the Solomon Sea lies in a zone of interaction between the Australian and Pacific tectonic plates, it was considered likely that Tertiary basins prospective for petroleum would be present. In 1969 the East Papua aeromagnetic survey revealed a magnetic low which was interpreted as a basin, here named the Trobriand Basin. A sedimentary section of some 3000 m, situated under shallow water was indicated.Amoco, Australian Oil & Gas and Southern Pacific Petroleum made application for and were granted exploration permit PNG/15P in June, 1971. The Group initially undertook field geological, aerial photographic and hydrographic surveys which revealed the presence of numerous Pliocene to Recent coral reefs throughout the permit and also indicated the likely nature of economic basement. Between April 1972 and May 1973, three marine seismic surveys by Western Geophysical produced 2250 km of reflection profiles. The seismic data suggest that the Trobriand Basin is an east-west trending graben filled with up to 5000 m of probable Miocene and younger sediments. Positive structures, of which several were interpreted as mid-Miocene reefs, were mapped.Two subsidised exploratory wells, Goodenough No. 1 and Nubiam No. 1, were drilled in 1973. Only minor and questionable hydrocarbon shows were encountered and both wells bottomed in Miocene volcaniclastics. The wells penetrated immature upper Tertiary sediments with low present and palaeo-geothermal gradients and consequently the sediments might be considered an unfavourable environment for petroleum generation. Nevertheless, the Trobriand Basin has not been adequately explored for hydrocarbon accumulations as only a portion of the Tertiary section has been evaluated in two widely-spaced wells.

RIVOLI-1 GAS DISCOVERY — EXMOUTH SUB-BASIN, WESTERN AUSTRALIA

1992 ◽  
Vol 32 (1) ◽  
pp. 94
Author(s):  
Philip J. Lawry ◽  
Paul A. Carter
Keyword(s):  
Seismic Data ◽  
Joint Venture ◽  
Depositional Environments ◽  
Geochemical Analysis ◽  
Seismic Surveys ◽  
Range Type ◽  
Exmouth Gulf ◽  
Marine Seismic ◽  
Gas Bearing ◽  
Made In

Offshore exploration in the Exmouth Gulf commenced with seismic surveys during the early 1960s and resulted in the first well Bundegi-1 being drilled in 1978. This well, situated on the Rivoli-Bundegi Trend, encountered an interpreted residual hydrocarbon zone in the Birdrong Sandstone, an 18 m untested hydrocarbon zone in the Learmonth Formation, and tight, possibly gas bearing sandstones in the Mungaroo Formation.Modern shallow-water marine seismic data acquired by the EP 325 Joint Venture during surveys in 1987 and 1988 allowed accurate mapping of the basal Cretaceous section and the distribution of the Birdrong Sandstone. Complex structuring in the Jurassic and Triassic section was also resolved with the modern data.The Rivoli gas discovery, approximately 4.5 km northeast of Bundegi-1, was made in August 1989, with the intersection of a 10.5 m hydrocarbon column consisting mainly of gas but with a very thin oil leg (0.2 m). The Birdrong Sandstone reservoir comprises 10 m of fluvial sandstones overlain by 7 m of marginal marine sandstones and provides an important calibration point for depositional environments in this unit. The Rivoli gas pool occurs in a simple, downthrown anticline sealed by Winning Group shales. Geochemical analysis of oil extracted from core, suggests an earlier charge of 'Rough Range-type' oil, possibly generated from pre-Jurassic source rocks.Several prospects and a variety of play types are recognised and considerable exploration potential remains to be tested along the Rivoli-Bundegi Trend.

scholarly journals Deep learning for low-frequency extrapolation from multioffset seismic data

Geophysics ◽  
2019 ◽  
Vol 84 (6) ◽  
pp. R989-R1001 ◽  
Author(s):  
Oleg Ovcharenko ◽  
Vladimir Kazei ◽  
Mahesh Kalita ◽  
Daniel Peter ◽  
Tariq Alkhalifah
Keyword(s):  
Deep Learning ◽  
Seismic Data ◽  
Signal To Noise Ratio ◽  
Waveform Inversion ◽  
Low Frequency ◽  
Low Frequencies ◽  
Seismic Surveys ◽  
Full Waveform ◽  
Frequency Components ◽  
Marine Seismic

Low-frequency seismic data are crucial for convergence of full-waveform inversion (FWI) to reliable subsurface properties. However, it is challenging to acquire field data with an appropriate signal-to-noise ratio in the low-frequency part of the spectrum. We have extrapolated low-frequency data from the respective higher frequency components of the seismic wavefield by using deep learning. Through wavenumber analysis, we find that extrapolation per shot gather has broader applicability than per-trace extrapolation. We numerically simulate marine seismic surveys for random subsurface models and train a deep convolutional neural network to derive a mapping between high and low frequencies. The trained network is then tested on sections from the BP and SEAM Phase I benchmark models. Our results indicate that we are able to recover 0.25 Hz data from the 2 to 4.5 Hz frequencies. We also determine that the extrapolated data are accurate enough for FWI application.

scholarly journals Thermomagnetic features of Pirapora region, central Brazil

2019 ◽  
Vol 2 (1) ◽  
pp. 22-29
Author(s):  
Suze Nei Pereira Guimarães ◽  
Valiya M Hamza
Keyword(s):  
Magnetic Layer ◽  
Aeromagnetic Survey ◽  
Seismic Surveys ◽  
Filtering Method ◽  
Model Studies ◽  
Central Brazil ◽  
The North ◽  
Maximum Value ◽  
Geothermal Model ◽  
East West

We report results of a detailed analysis of aeromagnetic survey data of Pirapora region, situated in the São Francisco Craton region, central Brazil. The main residual anomaly is wide, spanning over an area of about 9000 square kilometers, and has a maximum intensity of ± 300 nT. The analytic signal of the anomaly is located between 44.5°and 45.5° W and between 16.5° and 18.5 S and has a maximum value of about 0.028 nTm-1. Results of spectral analysis, based on matched bandpass filtering method, indicate that the anomaly is composed of signals arising from three different layers. The top layer is at depth shallower than 5 km while the intermediate one extends from 5 to 15 km depth. The bottom of deepest magnetic layer extends over depths varying from 20 to 55 km. Along an east-west belt, south of Pirapora anomaly, the depth to bottom of magnetized crust is less than 35 km and comparable to the thickness of the local crust obtained in seismic surveys. However, the thickness of the magnetized crust can exceed 35 km to the north and to the south of the Pirapora anomaly. This implies that the top layer of the mantle itself is magnetized. Results of geothermal model studies indicate Curie isotherm of 580oC may lie at depths greater than 35 km, along wide sections of the Pirapora region, within the São Francisco Craton.

SHELL'S OFFSHORE VENTURE, IN SOUTH AUSTRALIA

1978 ◽  
Vol 18 (1) ◽  
pp. 44
Author(s):  
R. K. Whyte
Keyword(s):  
Deep Water ◽  
Seismic Data ◽  
South Australia ◽  
Field Work ◽  
Seismic Survey ◽  
Total Expenditure ◽  
Aeromagnetic Survey ◽  
Well Drilling ◽  
Seismic Surveys ◽  
Geological Information

Offshore South Australia permit O.E.L. 38 was granted to Shell Development (Aust.) Pty. Ltd. on 1st January 1966. An aeromagnetic survey of 10,300 km, three seismic surveys totalling 10,300 km and five man months of coastal field work were carried out before the permit was reissued at the end of 1968 as three separate permits SA-5, SA-6 and SA-7 under the newly enacted joint offshore legislation. At that time Shell also secured two adjoining deep Water permits SA-10 and SA-11.In the period 1969-70 two seismic surveys totalling some 11,750 km were shot. Given geophysical results, a six well drilling programme was planned to commence early 1972. Two dry wells, Platypus-1 and Echidna-1 were drilled in early 1972 in SA-6 and SA-7, with Platypus-1 providing some geological encouragement.Several more prospects were found in SA-6 and SA-7 by the 1973 and 1974 seismic surveys, but these were so small that further work could not be economically justified. SA-6 and SA-7 were surrendered in late 1975 without further wells being drilled. Potoroo-1 was drilled in early 1975 in SA-5. It severely downgraded the prospectivity of that permit, leading to early relinquishment later in 1975, but provided vital geological information relevant to permits SA-10 and SA-11 where drilling was due to commence in 1978. A detail seismic survey in the latter two permits was shot in 1976. Prior to 1976, the main incentive for exploration of the deepwater play had been the apparent presence of a very large anticlinal trend in the central part of SA-10. Interpretation of the 1976 survey showed this trend to be non-prospective, and as a result SA-10 and SA-11 were relinquished in April, 1977. This ended a venture in which three wells were drilled and 24,546 km of seismic data recorded for a total expenditure of $15,837,000.

Formation geological depth image according to refraction and reflection marine seismic data

2017 ◽  
Vol 39 (6) ◽  
pp. 106-121
Author(s):  
A. O. Verpahovskaya ◽  
V. N. Pilipenko ◽  
Е. V. Pylypenko
Keyword(s):  
Seismic Data ◽  
Depth Image ◽  
Marine Seismic

PROCESSING AND IMAGING OF MARINE SEISMIC DATA FROM THE JEQUITINHONHA BASIN (BAHIA, BRAZIL)

2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Lourenildo W.B. Leite ◽  
J. Mann ◽  
Wildney W.S. Vieira
Keyword(s):  
Seismic Data ◽  
Sedimentary Basins ◽  
Study Results ◽  
Marine Seismic ◽  
Present Case Study

ABSTRACT. The present case study results from a consistent processing and imaging of marine seismic data from a set collected over sedimentary basins of the East Brazilian Atlantic. Our general aim is... RESUMO. O presente artigo resulta de um processamento e imageamento consistentes de dados sísmicos marinhos de levantamento realizado em bacias sedimentares do Atlântico do Nordeste...

SOUTH GEORGIA MICROCONTINENT: CURRENT TECTONIC SETTING FROM GPS AND MARINE SEISMIC DATA

2019 ◽  
Author(s):  
Ian W.D. Dalziel ◽  
◽  
Robert Smalley ◽  
Lawrence A. Lawver ◽  
Demian Gomez ◽  
...  
Keyword(s):  
Seismic Data ◽  
Tectonic Setting ◽  
South Georgia ◽  
Marine Seismic

scholarly journals A Machine Learning-Based Seismic Data Compression and Interpretation Using a Novel Shifted-Matrix Decomposition Algorithm

2021 ◽  
Vol 11 (11) ◽  
pp. 4874
Author(s):  
Milan Brankovic ◽  
Eduardo Gildin ◽  
Richard L. Gibson ◽  
Mark E. Everett
Keyword(s):  
Real Time ◽  
Seismic Data ◽  
Matrix Decomposition ◽  
Original Data ◽  
Velocity Estimation ◽  
Singular Vectors ◽  
Well Stimulation ◽  
Marine Seismic ◽  
Value Decomposition ◽  
Seismic Data Compression

Seismic data provides integral information in geophysical exploration, for locating hydrocarbon rich areas as well as for fracture monitoring during well stimulation. Because of its high frequency acquisition rate and dense spatial sampling, distributed acoustic sensing (DAS) has seen increasing application in microseimic monitoring. Given large volumes of data to be analyzed in real-time and impractical memory and storage requirements, fast compression and accurate interpretation methods are necessary for real-time monitoring campaigns using DAS. In response to the developments in data acquisition, we have created shifted-matrix decomposition (SMD) to compress seismic data by storing it into pairs of singular vectors coupled with shift vectors. This is achieved by shifting the columns of a matrix of seismic data before applying singular value decomposition (SVD) to it to extract a pair of singular vectors. The purpose of SMD is data denoising as well as compression, as reconstructing seismic data from its compressed form creates a denoised version of the original data. By analyzing the data in its compressed form, we can also run signal detection and velocity estimation analysis. Therefore, the developed algorithm can simultaneously compress and denoise seismic data while also analyzing compressed data to estimate signal presence and wave velocities. To show its efficiency, we compare SMD to local SVD and structure-oriented SVD, which are similar SVD-based methods used only for denoising seismic data. While the development of SMD is motivated by the increasing use of DAS, SMD can be applied to any seismic data obtained from a large number of receivers. For example, here we present initial applications of SMD to readily available marine seismic data.

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