Maintaining line of sight in oil and gas exploration: A case study from Mahakam Delta, Indonesia

2020 ◽  
Vol 39 (8) ◽  
pp. 558-565
Author(s):  
Balakrishnan Kunjan ◽  
Witan Ardjakusumah ◽  
Kevin McDonald ◽  
Hannah Booth ◽  
Seda Rouxel ◽  
...  

In all exploration processes, the evaluation of basins, permits, and individual prospects changes over time with incremental availability and quality of data, technical effort expended, and knowledge gained. The NU prospect, located in the Mahakam Hilir PSC (East Kalimantan), is an example in which geologic chance of success (GCOS) predictions can change over time with increasing acquisition and availability of geophysical and geologic data and the studies done on them. We show how studies done on any one prospect or group of prospects can progressively increase/decrease the chance of at least one success in an exploration campaign of several wells. After a series of four wells was drilled in the PSC, which did not deliver commercial success, a change in approach was required to continue exploration. This included the acquisition of airborne gravity gradiometry data, initial trial prestack depth migration (PSDM) reprocessing of two key 1989 vintage 2D lines, acquisition of vintage well data from four Sambutan Field wells, acquisition of nine vintage 2D seismic lines over the field, and PSDM reprocessing of the nine 2D seismic lines. All data were then integrated to build a new geologic model. As a result, the NU prospect GCOS progressively moved from less than 10% to nearly 40%.


2021 ◽  
Author(s):  
Megan Schmidt ◽  
Scott J. Davidson ◽  
Maria Strack

Abstract Oil and gas exploration has resulted in over 300,000 km of linear disturbances known as seismic lines, throughout boreal peatlands across Canada. Sites are left with altered hydrologic and topographic conditions that prevent tree re-establishment. Restoration efforts have concentrated on tree recovery through mechanical mounding to re-create microtopography and support planted tree seedlings to block sightlines and deter predator use, but little is known about the impact of seismic line disturbance or restoration on peatland carbon cycling. This study looked at two mounding treatments and compared carbon dioxide and methane fluxes to untreated lines and natural reference areas in the first two years post-restoration. We found no significant differences in net ecosystem CO2 exchange, but untreated seismic lines were slightly more productive than natural reference areas and mounding treatments. Both restoration treatments increased ecosystem respiration, decreased net productivity by 6–21 gCO2m− 2d− 1, and created areas of increased methane emissions, including an increase in the contribution of ebullition, of up to 2000 mgCH4m− 2d− 1. Further research on this site to assess the longer-term impacts of restoration, as well as application on other sites with varied conditions, will help determine if these restoration practices are effective.



2020 ◽  
Vol 50 (12) ◽  
pp. 1340-1351
Author(s):  
Laureen F.I. Echiverri ◽  
S. Ellen Macdonald ◽  
Scott E. Nielsen

In peatlands, microtopography strongly affects understory plant communities. Disturbance can result in a loss of microtopographic variation, primarily through the loss of hummocks. To address this, mounding treatments can be used to restore microtopography. We examined the effects of mounding on the understory vegetation on seismic lines in wooded fens. Seismic lines are deforested linear corridors (∼3 to 8 m wide) created for oil and gas exploration. Our objectives were to compare the recovery of understory communities on unmounded and mounded seismic lines and determine how recovery varies with microtopographic position. Recovery was evident in the unmounded seismic lines, with higher shrub and total understory cover at the “tops” of the small, natural hummocks than at lower microtopographic positions — much like the trends in adjacent treed fens. In contrast, mounding treatments that artificially created hummocks on seismic lines significantly changed understory communities. Mounded seismic lines had higher forb cover, much lower bryophyte cover, less variation along the microtopographic gradient, and community composition less similar to that of the reference sites than unmounded seismic lines due to higher abundance of marsh-associated species. Our results suggest that mounding narrow seismic lines can be detrimental to the recovery of the understory communities in treed peatlands.



2020 ◽  
pp. 10-18
Author(s):  
R. M. Bembel ◽  
M. R. Bembel ◽  
M. I. Zaboeva ◽  
E. E. Levitina ◽  
L. A. Sukhov

The inorganic concept of the formation of oil and gas deposits, based on the thermonuclear synthesis of helium and carbon, greatly increases the prospects for oil and gas exploration and development. Nuclear synthesis of hydrogen, helium and carbon, the main chemical elements that form hydrocarbons, not only occurs in the core and mantle of the Earth, but also energetically provides geosoliton depth migration of gases to deposits within the Earth's crust.



2011 ◽  
Vol 51 (1) ◽  
pp. 667
Author(s):  
Paul Rheinberg

Oil and gas exploration in Australia, both on and offshore, has been centred on a small number of proven petroleum provinces and—given the extent of prospective basinal area that exists—it remains relatively under-explored to this day. Since the 1970s, companies have progressively spent a smaller proportion of their exploration budgets on onshore and shallow water targets, where discoveries have been regular yet unspectacular, in favour of the deeper waters, where higher risks are involved but the potential exists for significantly higher returns. This activity has led to the discovery of more than of 150 Tcf of gas in the North Carnarvon, Browse and Bonaparte basins, the majority of which sits in deepwater areas. An absence of infrastructure and a lack of an adequate market meant that these huge discoveries lay undeveloped; however, with developments in technology and demand for gas in Asia set to surge into the next decade, these previously stranded fields are set to move into development, underpinning economic growth in Australia and ensuring that the country moves to the forefront of the LNG industry worldwide. This paper will examine upstream activity, both on and offshore, in Australia since 2000, a decade in which the country has become one of the most prominent destinations for exploration expenditure in the world. Following the exploration cycle from acreage release through to discovery, it will look at how trends and activity have changed over time and examine how successful the industry has actually been. It will explore the factors driving activity and the effects external forces such as regulatory changes, oil price and prevailing economic conditions have had on activity levels. No post-Conference paper is available for this presentation. No post-conference paper is available for this presentation.



2014 ◽  
Vol 2 (2) ◽  
pp. T57-T68
Author(s):  
Patricia Martinez ◽  
Mario Gimenez ◽  
Andres Folguera ◽  
Federico Lince Klinger

Gravity measurements and reinterpretations of previously released seismic lines were made, focusing on the provincial border between neighboring provinces San Juan and Mendoza. A Bouguer anomaly map was obtained after the processing of gravimetric data, which were previously filtered, to obtain the Bouguer residual anomalies used for studying the geologic structures located on the upper crust. The analysis of these Bouguer residual anomalies allowed identification of the Jocolí Basin in a foreland position within a triangle zone at the boundary of the Precordillera fold-and-thrust belt with the Sierras Pampeanas thick-skinned foreland province. The seismic images allowed interpretation of three horizons: Paleozoic, Triassic, and Tertiary-Quaternary ages. The authors have reinterpreted the seismic and well data and reconstructed gravity models for the area under study aiming at unraveling the deep structure of the region and identifying features with potential for oil and gas exploration.



2016 ◽  
Vol 10 (3) ◽  
pp. 117
Author(s):  
Priatin Hadi Widjaja ◽  
D. Noeradi ◽  
A.K. Permadi ◽  
Ediar Usman ◽  
Andrian Widjaja

Kajian geologi migas di Cekungan Tarakan relatif sangat kurang dibandingkan dengan Cekungan Kutai, diantaranya mengenai analisis stratigrafi sekuen yang lebih detil dan komprehensif, tingkat variasi lapisan sedimen di daerah transisi dengan laut dangkal sampai sedang dan keterkaitan dengan penentuan potensi migas. Padahal eksplorasi minyak dan gas bumi di Cekungan Tarakan, Kalimantan Timur telah mengalami proses waktu yang sangat panjang bahkan termasuk salah satu eksplorasi tertua di Indonesia. Namun eksplorasi di wilayah lepas pantai termasuk di timur Pulau Tarakan masih belum ditemukan lapangan migas yang bernilai ekonomis. Ini sangat berbeda dengan hasil eksplorasi Cekungan Kutai di lepas pantai dan laut-dalam yang telah mengalami kemajuan signifikan dalam 10 tahun terakhir setelah ditemukan beberapa lapangan migas laut-dalam seperti West Seno dan Gendalo. Berdasarkan pada pemerolehan data yang terdiri dari penampang seismik 2D, log sumur, rangkuman data biostratigrafi dan data check-shot, kajian dilakukan secara bertahap mulai dari analisis sekuen dan korelasi log sumur, interpretasi dan analisis seismik stratigrafi, pemetaan bawah permukaan, dan penentuan lokasi yang berpotensi migas. Tahapan metodologi kajian ini menggunakan beberapa perangkat lunak yang diproses secara integratif. Hasil akhir kajian dari integrasi peta struktur kedalaman dan peta isopach serta dukungan data petrofisik dari aspek kualitas batuan reservoir diperoleh dua lokasi yang berpotensi migas: Potensi Migas-1 di bagian tenggara dekat Pulau Tarakan merupakan jebakan struktur antiklin yang dikontrol sesar-sesar inversi dan Potensi Migas-2 di lepas pantai bagian timur wilayah kajian berupa jebakan struktur hidrokarbon sebagai sebuah antiklin yang memanjang relatif arah SEE – NWW. Kata kunci: Tarakan, sekuen, seismik, potensi migas Study of Petroleum geology in the Tarakan Basin is relatively less than in the Kutai Basin such as detailed and comprehensively sequence stratigraphy, variation of sediment layering from transition to outer-neritic zone and its related to determination of oil and gas potential locations. Oil and gas exploration in Tarakan Basin, East Kalimantan, has been carried out for the last a hundred years ago and its include as the oldest basin in Indonesia. Unfortunately, oil and gas field in eastern part of offshore Tarakan Island has not yet been discovered significantly. In contrast, offshore and deep-water oil and gas fields of Kutai Basin has been discovered significantly i.e. West Seno and Gendalo Fields. Based on data of 2D seismic in SEGY-files, well log in LAS-file, biostratigraphy and check-shot data, then steps of research followed by a sequence analysis, wells correlation, interpretation and analysis of seismic stratigraphy, subsurface mapping and determination of oil and gas potential locations. The results of this study are oil and gas potency 1 and potency 2. Potency 1 is located in south-eastern part of Tarakan Island where anticlinal traps are controlled by inversion faults. In contrast, potency 2 is an anticlinal trap located in offshore at the eastern part of the study area. Key words: Tarakan, sequence, seismic, oil and gas potential



Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 295 ◽  
Author(s):  
Cassondra Stevenson ◽  
Angelo Filicetti ◽  
Scott Nielsen

Seismic lines are linear forest clearings used for oil and gas exploration. The mechanical opening of forests for these narrow (3–10 meter) lines is believed to simplify microtopographic complexity and depress local topographic elevation. In treed peatlands, simplified microtopography limits tree regeneration by removing favourable microsites (hummocks) for tree recruitment and increasing the occurrence of flooding that reduces survival of tree seedlings. Little, however, has been done to quantify the microtopography of seismic lines and specifically the degree of alteration. Here, we measured microtopography at 102 treed peatland sites in northeast Alberta, Canada using a high precision hydrostatic altimeter (ZIPLEVEL PRO-2000) that measured variation in local topography of seismic lines and adjacent paired undisturbed forests. Sites were separated into four peatland ecosite types and the presence or absence of recent (<22 years) wildfires. Paired t-tests were used to compare microtopographic complexity and depression depth of seismic lines compared with adjacent forests. Microtopographic complexity on seismic lines was simplified by 20% compared to adjacent stands with no significant change between recently burned and unburned sites, nor between ecosites. Not only were seismic lines simplified, but they were also depressed in elevation by an average of 8 cm compared to adjacent forests with some minor variation between ecosites observed, but again not with recent wildfires. Thus, simplification of microtopographic complexity and the creation of depressions can persist decades after initial disturbance with some differences between peatland ecosites, implying the need for ecosite-specific restoration of topographic complexity. The importance of microtopography for tree regeneration on seismic lines remains an important question for reforestation of these disturbances and thus long-term recovery of habitat for species dependent on undisturbed peatlands, including woodland caribou.



1995 ◽  
Author(s):  
Richard F. Mast ◽  
D.H. Root ◽  
L.P. Williams ◽  
W.R. Beeman


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