Explorer Geophysical Corner

Seismic data are usually contaminated with noise, which, stated simply, refers to unwanted signal. Noise in seismic data can originate from various sources but processed seismic data may contain the following types of noise: random noise, steeply dipping coherent noise, aliased coherent noise that may appear to be random, and coherent multiples that are often subparallel to the reflectors of interest.

American Association of Petroleum Geologists (AAPG)
Explorer Article

New ground-breaking advances are currently being made at the Utah Frontier Observatory for Research in Geothermal Energy using methods borrowed from the oil and gas industry for unconventional hydrocarbon development. Recently, geothermal history was made when Utah FORGE successfully completed the first of two highly deviated deep wells in the hot, hard granite that will form the geothermal reservoir.

American Association of Petroleum Geologists (AAPG)
Explorer Article

Salt tectonics may be “an outlier in this country’s university training in structural geology,” but geologists entering the petroleum industry will almost certainly find themselves dealing with the topic, explained Mark G. Rowan of Rowan Consulting in Boulder, Colo. A growing understanding of how they form – especially since the 1980s – has been helpful in increasing their importance to exploration and production. Rowan discussed “Salt Diapirs – What Are They, How Do They Form and What is Their Role in Hydrocarbon Exploration?” at the recent Visiting Geoscientist Program Super Session organized by AAPG and the AAPG Foundation.

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American Association of Petroleum Geologists (AAPG)
Explorer Geophysical Corner

Last month we looked at the reasons why, as geoscientists, we need low frequencies. We also reviewed the sensors used to receive the reflected seismic signals and the recording instruments. This month’s article will address some of the issues of the seismic source. In other words, how do we get the required low frequency energy into the Earth? The two most frequently used sources for land acquisition are vibrators and explosives. We will assess the operational and cost differences between them and the advantages and disadvantages of each.

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American Association of Petroleum Geologists (AAPG)
Explorer Article

Last year started with promise for the Colombian offshore industry. Shell EP Offshore Ventures Limited and Ecopetrol, S.A. signed an agreement for Shell to acquire an interest in and operate the Fuerte Sur, Purple Angel and Col-5 blocks located in the southern Colombian Caribbean basin. Noble Energy opened an office in Barranquilla and announced plans to drill a prospect at 8,500 feet on the Col-3 block in the Guajira Basin in northern Colombia. Ecopetrol and Petrobras prepared to mature the 2014 Orca discovery on the Tayrona block, also in Guajira. Then COVID-19 came to the Americas in March 2020, and everything changed.

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American Association of Petroleum Geologists (AAPG)
Explorer Geophysical Corner

For many years the geophysical industry has spent considerable time and effort on improving the high-frequency content of recorded seismic data in the pursuit of higher resolution. However, in the last two decades we have seen an increased interest in extending the bandwidth of our data toward lower frequencies as well. In this series of two articles, I will address the reasons we need low-frequency information, the issues related to its acquisition for onshore projects and discuss the equipment and methods being used.

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American Association of Petroleum Geologists (AAPG)
Explorer Historical Highlights

Winthrop Rockefeller was the grandson of John D. Rockefeller and the fifth of six children of John D. Rockefeller Jr. The eldest Rockefeller organized and incorporated the Standard Oil Company in 1870. By the early 1880s, Standard Oil had a near-monopoly of the U.S. petroleum industry. At his retirement, Rockefeller was said to be worth $1.5 billion – the richest man in the world. He was also considered the world’s greatest philanthropist, giving more than $500 million to educational, scientific and religious institutions. Determined to learn the family’s oil business “from the ground up,” Winthrop worked at Standard Oil of New Jersey’s Bayonne refinery for a few weeks in June and July of 1933.

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American Association of Petroleum Geologists (AAPG)
Explorer Geophysical Corner

This study is primarily based on a 3-D seismic dataset that covers 1,107 square kilometers of the deepwater Ceará Basin. For this demonstration, the seismic cube was cropped and extends over an area of 765 square kilometers. It covers part of Premier Oil, Cepsa, Chevron and Ecopetrol exploration blocks, as well as ANP’s blocks of permanent offer. Here we present a broad overview of the seismic geomorphology of the study area aiming at delineating the turbidite channels, as the sands are deposited in the channels and can accumulate the hydrocarbons, which can be exploited for the benefits of the petroleum industry, as well as discuss a pitfall associated with the cropping of seismic data.

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American Association of Petroleum Geologists (AAPG)
Explorer Article

'Molly Turko, even in these dark times of COVID and decreased worldwide energy demand, is at heart an optimist. “There is always a light, you just have to know where to look,” she said. And she feels that the Anadarko Basin, a place she has spent the last 10 years of her professional life, is a great place to start looking. For Turko, who has worked in multiple basins in the United States, including the Ardmore, Powder River, Appalachian, onshore Gulf Coast and Rocky Mountain basins, said the Anadarko, along with the adjacent Wichita Uplift, may hold the most attractive possibilities.

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American Association of Petroleum Geologists (AAPG)
Explorer Historical Highlights

During the 1980s, early prospecting in deepwater margins was the simple extension of prolific updip producing basins that were charged. However, the migration of petroleum exploration and development into deepwater was fraught with challenges. For engineers and geologists, one of our biggest challenges was to overcome our collective lack of understanding about the geology of deepwater. We had to revisit everything we thought we knew, one paradigm shift after another.

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American Association of Petroleum Geologists (AAPG)
DL Abstract

Around 170 million years ago, the Gulf of Mexico basin flooded catastrophically, and the pre-existing landscape, which had been a very rugged, arid, semi-desert world, was drowned beneath an inland sea of salt water. The drowned landscape was then buried under kilometers of salt, perfectly preserving the older topography. Now, with high-quality 3D seismic data, the salt appears as a transparent layer, and the details of the drowned world can be seen in exquisite detail, providing a unique snapshot of the world on the eve of the flooding event. We can map out hills and valleys, and a system of river gullies and a large, meandering river system. These rivers in turn fed into a deep central lake, whose surface was about 750m below global sea level. This new knowledge also reveals how the Louann Salt was deposited. In contrast to published models, the salt was deposited in a deep water, hypersaline sea. We can estimate the rate of deposition, and it was very fast; we believe that the entire thickness of several kilometers of salt was laid down in a few tens of thousands of years, making it possibly the fastest sustained deposition seen so far in the geological record.

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Request a visit from Frank Peel!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Three-dimensional (3D) seismic-reflection surveys provide one of the most important data types for understanding subsurface depositional systems. Quantitative analysis is commonly restricted to geophysical interpretation of elastic properties of rocks in the subsurface. Wide availability of 3D seismic-reflection data and integration provide opportunities for quantitative analysis of subsurface stratigraphic sequences. Here, we integrate traditional seismic-stratigraphic interpretation with quantitative geomorphologic analysis and numerical modeling to explore new insights into submarine-channel evolution.

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Request a visit from Jacob Covault!

American Association of Petroleum Geologists (AAPG)
VG Abstract

In comparison with the known boundary conditions that promote salt deformation and flow in sedimentary basins, the processes involved with the mobilization of clay-rich detrital sediments are far less well established. This talk will use seismic examples in different tectonic settings to document the variety of shale geometries that can be formed under brittle and ductile deformations.

Request a visit from Juan I. Soto!

American Association of Petroleum Geologists (AAPG)

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