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Africa (Sub-Sahara) Namibia's Ministry of Mines and Energy approved a 1-year extension to its offshore license covering Block 2714A to Chariot Oil & Gas. The extension will allow for the completion of its analysis of the drilling results of the Kabeljou-1 exploration well. Petrobras (30%) is the operator in partnership with Chariot (25%) and BP (45). Asia Pacific The Basset West-1 well encountered 25 ft of gas pay in Jurassic sandstones on the Browse basin offshore Western Australia. The well was drilled to a total depth of 5240 m. Total E&P Australia (50%) is the operator in partnership with Santos (30%) and Murphy Oil (20%). Australia's government awarded 13 new offshore petroleum exploration permits after receiving 23 bids for 15 blocks. A total of USD 172 million will be spent exploring the areas, which are located offshore Western Australia and Tasmania, over the initial 3 years of the permit terms.
Africa (Sub-Sahara) Sonangol's deepwater Orca-1 well encountered oil in the presalt layer of Block 20/11 in the Cuanza basin offshore Angola. The well reached a measured depth of 12,703 ft. Initial well tests saw flow rates of 16.3 MMcm/D of gas and 3,700 BOPD. Cobalt International Energy (40%) is the operator, with partners Sonangol Research and Production (30%) and BP Exploration Angola (30%). Asia Pacific Premier Oil's Kuda Laut-1 well in Indonesia's Tuna production sharing contract has encountered 183 net ft of oil-bearing reservoir and 327 net ft of gas-bearing reservoir. Following evaluation operations, the well will be sidetracked to drill the Singa Laut prospect in an adjacent fault block. Premier is the operator (65%), with partner Mitsui Oil Exploration Company (35%).
Sonangol's deepwater Orca-1 well encountered oil in the presalt layer of Block 20/11 in the Cuanza basin offshore Angola. The well reached a measured depth of 12,703 ft. Initial well tests saw flow rates of 16.3 MMcm/D of gas and 3,700 BOPD. Cobalt International Energy (40%) is the operator, with partners Sonangol Research and Production (30%) and BP Exploration Angola (30%). Premier Oil's Kuda Laut-1 well in Indonesia's Tuna production sharing contract has encountered 183 net ft of oil-bearing reservoir and 327 net ft of gas-bearing reservoir.
Colombia’s New Ambitions Include Caribbean and Shale Development, But Are They Achievable? You have access to this full article to experience the outstanding content available to SPE members and JPT subscribers. To ensure continued access to JPT's content, please Sign In, JOIN SPE, or Subscribe to JPT At some point during the first half of this year, Colombia replaced politically and economically crippled Venezuela as Latin America’s third-largest oil-producing country. Since Brazil ended state-owned Petrobras’ monopoly and opened up its industry to international companies in the late 1990s, the country’s oil output has almost tripled as it found and tapped into its giant offshore presalt fields. Output from Mexico’s state-owned Pemex, meanwhile, has fallen to its lowest level since at least 1990, and President Andrés Manuel López Obrador is working to stymie energy reforms implemented in 2013 to rejuvenate industry in the country.
An investigation of the factors controlling the regional distribution of unconventional reservoirs - organic rich shales / carbonates - in Latin America, included the analysis and identification of the vertical relationship and characteristics between the reservoirs of different basins. The analysis provided evidence to understand why different formations in different basins have similar potential and supports a proposed interpretation.
The study is based on the analysis of the main source rocks which are being developed or targeted as unconventional reservoirs. These reservoirs grouped by basin, age, formation, and characteristics such as depositional environment, extension, lithology, thickness, depth, organic content, and kerogen type were analyzed. More than 20 basins in Latin America and 30 formations considered source rock, from Silurian to Cretaceous, have been evaluated (
Evaluated Basins, Organic Rich Shales and Age.
The distribution of relevant Latin America's unconventional resources is related to a sum of very well-known global factors closely associated with the extent of the Jurassic- Cretaceous seas in times of high eustatic levels, when most of the sediments generating unconventional resources were deposited. Proper interpretation and knowledge of the distribution of Mesozoic seas and their coeval events enables predicting the location of unconventional reservoirs, understanding the reason for their existence, and anticipating the main characteristics to be found in these rocks.
The geographical distribution of some of the most representative unconventional reservoirs in the main basins of Latin America relates to the regional event causing the deposition of these rocks during the Upper Cretaceous. Sediments of this age include formations in the north of South America, such as La Luna, Querecual, Naparima Hill and equivalents, which are synchronous with deposits such as Eagle Ford and Agua Nueva formations. The Upper Jurassic and Lower Cretaceous comprise a second group of unconventional reservoirs among which is the extended Vaca Muerta formation.
Understanding the relationship between occurrence, genesis and distribution of unconventional reservoirs in Latin America is fundamental to predicting the presence of these reservoirs, using global factors such as tectonic plate distribution and sea level. The summary with the characteristics of each of these reservoirs can be used as a guide to understand the magnitude of the hydrocarbon potential.
Pico, Antonio (Pacific Rubiales Energy) | Aboud, Jesús (Pacific Rubiales Energy) | Parraga, Felipe (Pacific Rubiales Energy) | Martinez, Jose Antonio (Pacific Rubiales Energy) | Lopez, Gonzalo (Pacific Rubiales Energy)
The central region of the Llanos Basin in Colombia has been characterized by an extensional structural style, where the overall fault pattern consists of normal faults oriented approximately N30°E, dipping East. The structures of the oil fields in Casanare Province have been defined by this type of faults. In this work we establish, for the Casanare Province, the existence of compartmentalized structures formed by the junction between N60° E en-échelon faults and N30E normal faults. In this interpretation, en-échelon faults and folds play a major role in oil accumulations. 3D seismic multi attributes, including volume curvature, coherency and ant tracking, were used to reduce the uncertainties associated with the seismic and well data in order to improve geological constraints, in folds, faults and associated fracture zones. As a result, a new strike-slip fault pattern was interpreted, consistent with a wrench zone, as proposed by Wilcox, et al (1973).
The rock quality of nine major hydrocarbon basins of Colombia was analyzed using a new technology called digital rock physics (DRP). The study consisted of image and computational analysis on 140 wells from the national core repository “Bernardo Taborda” provided by the Agencia Nacional de Hidrocarburos (ANH). Targeting shale rich reservoirs, the three main basins of study were the Catatumbo, Llanos, and Middle Magdalena Valley. A DRP analysis that scaled resolution with sample size was performed until individual pores were visible and computations of porosity and directional permeability could be calculated. Numerically efficient fluid flow algorithms allowed for the computation of shale reservoir properties and provided clear 3D renderings of pore and organic matter structures. Once core analysis was complete, DRP data was integrated with well log data in order to create an upscaled petrophysical model for 134 wells found in these basins.
Within these three basins the La Luna and Gacheta formation data are presented here. Multiple digital imaging techniques and computations were used to determine properties such as mineralogy, porosity, organic content, porosity associated with organic content and absolute permeability. Upon completion, a comparison was made with the Eagle Ford and Wolfcamp formations from North America. The data show the rock qualities from the Colombian samples are comparable.
Vertical wells are drilled in the Colombian foothills with various types of drill bits, including polycrystalline diamond compact bits (PDC), tungsten carbide insert bits (TCI), and impregnated (impreg) drill bits. With an operator’s support a new 14¾-in. impreg bit was designed using an innovative new cutting structure to complete a challenging interval. This bit was paired with a low-speed power section & a high-speed power section in the bottom hole assembly (BHA) for two runs in the same well. Both runs did well but the operator found the low-speed BHA to be a better match for the automated drilling system tool that was also in the BHA.
The multi-layered 14¾-in. section consists of hard and abrasive sandstone, interbedded claystone, and siltstone formations. The majority of drill bits suffer short runs due to severe wear in the outer region (shoulder) of the bit. The new impreg design was developed to increase run length and avoid unnecessary trips in the challenging formations.
The impreg bit uses diamond impregnated segments imbedded in blades comprised of diamond grit matrix material to create a cutting structure with variable wear along the bit face. This particular combination of diamond and matrix specifically corresponded to the application and improved overall aggressiveness and durability in the shoulder.
Typically, to drill efficiently, impregs are paired with high-speed motors or turbines (500-1200 rpm) due to the low depth of cut. This new impreg design, however, was able to successfully drill on two different BHAs. The first was with a high-speed power section (0.93 rev/gal) and drilled 108 ft at 4.9 ft/hr. The bit did not show signs of wear and was used on a second BHA with a low-speed power section (0.15 rev/gal) that drilled another 665 ft at 3.9 ft/hr. The impreg’s overall performance was 773 ft drilled at 4.0 ft/hr. The bit showed only minor wear when compared to offset wells (15% vs. 80 to 100% cutting structure wear).
The addition of the impregnated segments and mixed grit combination improved the cutting structure durability. This provides an opportunity to further develop the grit, matrix, and impregnated segment combination to increase the aggressiveness of the bit to drill faster and lower the overall drilling cost of a well.
This article will explain the benefits of the new technology and discuss how impregs effectively drilled hard and abrasive formations in a low-revolution application.
Inherited structures are responsible for the segmentation of hydrocarbon resources in the Cenozoic retroarc belt of South America. We use an 8000km-long strike cross-section from northern Colombia to central Argentina to illustrate how these inherited elements influence structural styles and resource distribution. Three events are responsible for segmentation of retroarc sub-basins. Late Ordovician terrane accretion in Argentina and Chile created a crustal welt oriented obliquely to the modern-day Andes. This long-lived Transpampean arch lacks thick Paleozoic sediments and Bolivian-style hydrocarbon occurrences, which are the most significant accumulations in the central Subandes. Important source rocks in the Chaco, Bene, Madre de Dios and Ucayali basins were deposited in middle and late Paleozoic time to the northeast of this arch. The arch shortens by thick-skinned contraction of rift basins and basement. A widespread mid-Carboniferous event rejuvenated pre-existing regional highs and created new contractional uplifts, most conspicuously in Peru. Lastly, protracted Mesozoic rifting is responsible for the second volumetrically important quantity of discovered hydrocarbons in the Subandean belt. In Argentina, the Neuquén (Jurassic), Cuyo (Triassic) and Salta (Cretaceous) rifts trend at moderate to high angles to the Andes. The Neuquén, following a long history of conventional production, is now being evaluated for unconventional resource potential from upper Jurassic and lower Cretaceous shales. The Cuyo basin produces from several reservoirs in inverted fault blocks. Several small fields are also present within and flanking the Salta rift. In central Peru, the Jurassic Pucara Formation has elevated TOCs due to deposition in restricted half-graben basins, but may have matured prior to formation of Subandean traps in the Late Cenozoic. In Colombia, Early Cretaceous normal faulting lead to thickening of section from the Llanos basin westward into the Eastern Cordillera. Fault blocks became covered by well-known, world class Cenomanian-Santonian sources, and later inverted, creating and filling several large closures in the Llanos foothills. In comparing the Subandes to foldbelts elsewhere, it is the rule rather than the exception that petroleum systems robustness varies on a scale of a few hundred kilometers in the strike direction, as most continents possess heterogeneous basement, superposed deformations, and sub-basin stratigraphy that vary over roughly that dimension.
Innumerable descriptions have been published on the geometry and kinematic evolution of fold-thrust belts around the globe, utilizing various data types. To a lesser degree, attempts have been made to relate those structural styles and attributes to the distribution of hydrocarbon resources in petroleum basins (e.g. Cooper, 2007). Both types of synthesis have focused mainly on two-dimensional, cross-sectional evaluations relating, for example, sedimentary wedge taper to wavelength of structural imbrication or mechanical stratigraphy to decollement preferences.
In this paper we extend our focus to the third (strike) dimension of the Subandean foldbelt, in order to address a) over what length scales do the structural styles of foldbelts change and for what reasons?, b) how does the original sedimentary configuration and mechanical stratigraphy of a basin influence or control subsequent structural development of the contractional system?, and c) how do these stratigraphic and structural changes in the strike direction conspire to yield boundaries or transitions between more and less robust petroleum systems?.
Becerra, Marta Elena (Occidental de Colombia) | Hampton, David (Occidental de Colombia) | Llamosa, Oscar (Occidental de Colombia) | Perdomo, Christian (Occidental de Colombia) | Malagon, Claudia (Occidental de Colombia) | Torres, Mauricio (Occidental de Colombia) | Patiño, Cesar (Ecopetrol)