Analisis Atribut Seismik Instantaneous Frequency Untuk Sebaran Reservoir Batupasir Formasi Tensleep Lapangan Teapot Dome

Lapangan Teapot Dome berada di Wyoming Tengah, Amerika Serikat. Lapangan ini tercatat sebagai 100 lapangan penghasil minyak terbesar di Amerika Serikat dengan cadangan yang terbukti sebesar 42.515.000 barrel. Lapangan ini berada dekat dengan tepi barat daya Cekungan Powder River. Bagian terdalam dari Cekungan Powder River terdiri dari hampir 5.500 meter batuan sedimen, dan sekitar 2.440 meter dari sedimen tersebut merupakan sedimen non marin yang berumur Kapur Akhir dan batuan sedimen klastik Tersier yang berhubungan dengan Orogenesis Laramide. Penelitian ini difokuskan pada bagian Pennsylvanian, khususnya pada bagian Top Sand B. Lapisan ini merupakan lapisan batupasir yang cukup tebal dengan Eolian Dunes. Pemetaan yang dilakukan ini untuk mengetahui sebaran reservoir batupasir pada Top Sand B dengan analisis atribut seismik menggunakan atribut instantaneous frequency dengan menggunakan data seismik 3D Post Stack Time Migration dengan menggunakan 3 sumur sebagai pengontrol untuk formasi dan kedalaman. Berdasarkan hasil analisis atribut seismik menunjukkan bahwa atribut instantaneous frequency dapat menggambarkan sebaran reservoir batupasir pada bagian Top Sand B dengan perubahan yang dapat dilihat berdasarkan perubahan warna dalam bentuk peta. Dengan dominasi persebaran batupasir berada di wilayah bagian selatan Lapangan Teapot Dome. Hal ini juga dipengaruhi oleh struktur patahan pada Formasi Tensleep.

Understanding the Facies Architecture of a Fluvial-Aeolian of Tensleep Formation Using a Machine Learning Approach

Many aeolian dune reservoirs are built from various dune types, and many may remain unrecognized in subsurface work. The challenge is to tackle the complex geological architecture of dune types within the Teapot Dome dataset caused by wind and water erosion. Machine Learning (ML) helps predict facies architecture away from boreholes using seismic attributes and facies logs. It provides a detailed understanding of the facies architecture analysis of the relationship between the fluvial–aeolian environment in Tensleep Formation based on seismic and well data. It allows operators to wisely assess their hydrocarbon reservoir, improve safety, and maximize oil and gas production investment. The data from the Teapot Dome field (Naval Petroleum Reserve No.3 - NPR-3) provides a good testing ground for Machine Learning, as it is easy to validate and prove its value. This study will show how the ML supervised learning method incorporating Neural Network Seismic Inversion (NNSI) can successfully create porosity log and facies volumes. Moreover, unsupervised learning using Multi-Resolution Graph-based clustering (MRGC) can be used to classify the facies logs. NNSI has 0.963 for the cross-correlation coefficients for all wells. The ML approach was used to help recognize the type of aeolian dune reservoirs in the subsurface and correlate the well log and facies volumes. In addition, ML allowed the distinct sequences and reconstruction of their depositional history in the Tensleep Formation. This study also refers briefly to other examples of fluvial-aeolian facies architecture worldwide. It successfully found the ancient model in an existing modern fluvial-aeolian environment, revealing hidden information about facies architecture based on the geometrical shape of geobodies in the oil-producing reservoir in the Tensleep Formation.

Tempest

Chapter four explores Harry Sinclair's involvement in the notorious Teapot Dome oil scandal. Republican Warren G. Harding's landslide victory in the 1920 presidential election marked a new direction in American politics, ending the Progressive Era and ushering in a pro-business climate that would further enrich men like Sinclair and facilitate the return of American horseracing to national prominence. New secretary of the interior Albert B. Fall transferred oil reserves held by the US Navy in Wyoming to Sinclair. As news of the shady deal spread, Sinclair debuted his colt Zev, named after the oilman's attorney, William Zevely, who was a facilitator of the corrupt bargain. Zev would surpass Man o' War's all-time American earnings record, and his twenty-three career wins would include scores in the Kentucky Derby, Belmont Stakes, and the Race of the Century against English champion Papyrus.

Introduction

On October 20, 1923, at Belmont Park in New York, Kentucky Derby champion Zev toed the starting line alongside Epsom Derby winner Papyrus, England's top three-year-old colt. Few happenings had ever been covered so closely by American newspapers as the spectacle officially dubbed the International Race. The extraordinary hype surrounding the event was even more notable considering that only a few years earlier Thoroughbred racing had been on the brink of Progressive-era extinction in the United States. But following a post-World War I political sea change in the United States, in what would later be remembered as a "golden age" of sport, Americans rallied around the horse that was, in the words of its owner Harry F. Sinclair, "racing for America," while Sinclair was engaged in a scheme to defraud the United States of millions of barrels of publicly owned oil in one of the most notorious instances of political corruption in American history -- the Teapot Dome scandal. America First examines the postwar revival of American horseracing, culminating in the intercontinental showdown between Zev and Papyrus, that captured some of the incongruity and contradiction of 1920s America.

Magnificent Losers

Chapter Seven covers the fallout from the Race of the Century. After being embraced as "magnificent losers" in America, team Papyrus returned home to a disappointed nation full of critics of the entire endeavor. The score between Zev and My Own was settled by another blockbuster event, at Latonia Race Track. Nationally, promoters capitalized on the publicity of the International Race to build support for the expansion of horseracing and legalized gambling. With his triumph in the International Race, Earl Sande had reached the height of sports celebrity. But personal and professional challenges mounted, and he would die in an Oregon nursing home, nearly forgotten by the sports industry that had made him famous. Though Sinclair's acquittal on federal bribery charges related to his Teapot Dome scheme would shock many observers, he served nearly seven months in the Washington Asylum and Jail for contempt of the Senate and jury tampering.

APLIKASI INVERSI POST-STACK DAN GEOSTATISTIK UNTUK KARAKTERISASI RESERVOAR BATUPASIR FORMASI LAKOTA LAPANGAN TEAPOT, WYOMING, USA

Penelitian menggunakan metode inversi post-stack dan geostatistik telah dilakukan pada Formasi Lakota Lapangan Teapot Dome, Wyoming, Amerika Serikat. Tujuan dilakukannya penelitian ini adalah untuk mengkarakterisasi reservoar Batupasir Formasi Lakota, hak milik RMOTC dan U.S.Department of Energy. Metode yang digunakan pada penelitian ini adalah inversi post-stack metode modelbased untuk mendapatkan nilai AI dari volume seismik dan aplikasi geostatistik menggunakan analisis variogram, Kriging with External Drift dan Simulasi Gaussian bertujuan untuk mendapatkan distribusi sifat fisis reservoar secara lateral dari data sumur. Hasil inversi modelbased menunjukkan nilai impedansi Formasi Lakota berada pada rentang 28000-36000 ft/s*g/cc yang mengindikasikan bahwa Formasi Lakota merupakan interbedded shaly sand. Pembuatan layering reservoar dari volume AI menjadi empat map bertujuan untuk mendapatkan persebaran sifat fisis reservoar yang lebih akurat menggunakan metode geostatistik. Hasil dari metode geostatistik menghasilkan nilai porositas total berada pada rentang 20 – 30 % dan Vshale memiliki rentang nilai 10 – 40 % pada keempat layer map tersebar pada daerah Barat Laut yang termasuk ke dalam zona tight (nilai AI > 30000 ft*s/g*cc). Daerah tersebut diindikasikan sebagai area yang berprospek dan rentang nilai sifat fisis tersebut diklasifikasikan sebagai karakteristik reservoar yang baik. Reservoar batupasir yang tersturasi gas berlokasi di sekitar sesar normal dengan orientasi Timur Laut – Barat Daya, yang dapat ditunjukkan dengan bright amplitude pada data seismik dan nilai impedansi rendah. Dua sesar normal mayor berorientasi Timur Laut – Barat Daya membentuk two way dip closure trap berpreran sebagai jebakan hidrokarbon gas pada Formasi Lakota yang telah terbukti dengan adanya sumur produksi 41-2-X-3, 53-LX-3 dan 56-LX-10 berdasarkan data produksi Lapangan Teapot.Kata Kunci: Formasi Lakota, Geostatistik, Inversi Post-stack, Shaly-sandThe research using post-stack inversion and geostatistical method has been conducted on Lakota Formation, Teapot Dome Field, Wyoming, USA. The aim is to obtain reservoir characteristics and physical properties of Lakota Sandstone, copyrights of RMOTC, U.S Department of Energy. The method used in this research consist of Post-stack inversion modelbased method to obtain Acoustic Impedance of seismic volume and geostastical method using variogram analysis, Kriging with External Drift and also Gaussian simulation to obtain physical properties distribution laterally from well data. The result of modelbased inversion shows the impedance value of Lakota Formation has the range 28000-36000 ft/s*g/cc. It indicates that Lakota Formation has interbedded shaly-sand characteristics. The inversion result is divided into four layers and sliced into four maps to obtain physical properties distributin of Lakota Formation more accurately. The result of geostatistical method yields Total Porosity value of four maps on Lakota Formation has 20 – 30 % and Vshale 10 – 40% scattered in Northwest area of Teapot Field represents a tight zone (Acoustic Impedance value > 30000 ft/s*g/cc), which is indicated as prospective area and also those physical properties values classified as good reservoar characteristics. Sandstone reservoir which saturated by gas is located around normal fault with Northeast – Southwest orientation. It can be seen by bright amplitude on seismic data and low impedance value. Two major normal fault with Northeast – Southwest orientation forming two way dip closure trap has the role of gas brine zone trap of Lakota Formation. The existing of gas zone was proven by production wells 41-2-X-3, 53-LX-3 dan 56-LX-10 from Teapot Production Data.Keywords: Geostatistics, Lakota Formation, Post-stack Inversion, Shaly-sand