Testing and gathering data from a well to evaluate the potential of a new field is a common practice in the oil and gas industry. However, performing this task in ultra deep water presents significantly greater challenges to the operator and service providers, since testing in the depths required for the subject well had not previously been attempted, there were concerns of problems that might occur in maintaining response times and control of the test equipment. This paper will present the innovative solution that was devised to perform the testing in the deep water well. The equipment, the well, location condition, and procedures were used to safely and efficiently perform the evaluation testing will be discussed.
In Microbial Enhanced Oil Recovery(MEOR) processes, microbe(s) and nutrients are injected into a reservoir, and the microbe increases and produces metabolites such as polymers, surfactants, gases, and/or acids in the reservoir. These metabolites help to mobilize the residual oil. Our research group possesses a microbe Clostridium sp. TU-15A which can produce a water-soluble polymer in the molasses medium and increase the viscosity of the culture solution up to 70mPa•s(at38.3s-1) or higher by a 10 day cultivation. And it was shown by flooding experiments that this microbe was very effective for enhancing the oil recovery5). There seems to be no comprehensive model for MEOR with a microbe producing a water-soluble polymer. In the present study, the experimental data were formulated for developing a numerical model to analyze the performance and the mechanism of MEOR with a microbe producing the water-soluble polymer. In this paper, the concept of this model is discussed and the mathematical model described. The model consists of two phases(oil and water) and five components(oil, water, microbe, nutrient, and metabolite). The model includes almost all cesses of MEOR such as growth and death of microbe, consumption of nutrient, production of water-soluble polymer, increase of water viscosity, change of the flow profile in a reservoir, and enhancement of oil recovery.
Planktonic foraminiferal biostratigraphy is established for the late Pliocene Kuwae Formation exposed along the Tainai River, Kitakanbara district, Niigata Prefecture, central Japan. The Orbulina universa/Globorotalia ikebei Zone(PF 6) and the Neogloboquadrina pachyderma(dextral)/Globorotalia orientalis Zone(PF 7) of Maiya(1978) are recognized in the Kuwae Formation. In addition, No. 3 Globorotalia inflata bed which is characterized by the abundant occurrence of G. inflata group(G. orientalis and G. inflata praeinflata) is identified in the Kuwae Formation. The probable base of the No. 3 G. inflata bed which defines the base of the Nishiyama Stage lies between the FO(first occurrence) of Neodenticula koizumii(diatom, 3.5Ma) and RI(rapid increase) of N koizumii(3.0-3.1Ma), and is dated at about 3.4Ma by interpolation. However, it needs more data of planktonic foraminiferal analysis to confirm the base of the No. 3 G. inflata bed. Globorotalia inflata group occurs intermittently in the Kuwae Formation, suggesting intermittent inflow of relatively warm current into the Sea of Japan during late Pliocene. Systematic code numbers(PF 1-PF 9) are given to the zones of the late Cenozoic planktonic foraminiferal zonation of Maiya(1978).
Diatom biostratigraphy was examined for the upper Miocene to Pliocene sequence distributed in the Yufutsu oil and gas field located in southern central Hokkaido, Japan. The Denticulopsis praedimorpha and Denticulopsis dimorpha Zones were recognized in thin volcanic reworked sediment with glauconite, which overlies just above the Takinoue volcanics oil reservoir. The result indicates that the condensed glauconite bed had been formed for a long time, from the end of Takinoue volcanic activity through the D. dimorpha Zone. Siliceous sediments overlaying the glauconite bed are correlated to the upper part of the Thalassionema schraderi and Rouxia californica Zones. The siliceous sediment is unconformably covered by sandy sediment. Its basal part is correlated to the Neodenticula koizumii-Neodenticula kamtschatica Zone. The N. kamtschatica Zone is completely missing in the field whereas it is thickly developed at the Yufutsu-oki wells located about 20km offshore. Based on the diatom biostratigraphy and interpretation of seismic profiles, the condensed glauconite bed is correlated to the middle to upper Miocene Fureoi and Karumai Formations. The interval of "the Biratori and Karumai Formations" by several authors in the field is correlative to the upper Miocene Nina Formation typically distributed along the Sarugawa river near the Biratori city. "The Nina Formation and Quaternary System" in the field is correlated to upper Pliocene and Quaternary.
Nippon Oil Exploration Ltd. farmed into the WA-191-P permit located in the Dampier Sub-basin, North West Shelf, off Australia in March, 1997. Exploration Well, Pitcairn-1 was drilled immediately after the farm-in, and oil was found at the top of Upper Jurassic Angel Formation sandstone. After the drilling of Pitcairn-1, it turned out that there is a marked difference in a time-depth relation between Pitcairn-1 and a nearby well previously drilled, and also that there is a lateral change on the stacking velocity map generated from 2D seismic data. The velocity trends were carefully reviewed with the existing check shot data and seismic stacking velocities, with the result that lateral change in p-wave velocity is conspicuous especially in the Tertiary Mandu Formation which mainly consists of carbonates, and this velocity change corresponds to the interval indicating a distinct clinoform, suggesting that the lithology laterally changes. Depth conversion using a newly constructed velocity model demonstrated the presence of another anticlinal closure with a low relief to the north of Pitcairn-1. For the better definition of depth mapping with dense velocity data, a new 3D seismic acquisition was conducted in the western part of WA-191-P including Pitcairn and other leads. After constructing a new depth map using a detailed velocity model utilizing this 3D seismic data, Mutineer, Norfolk and Exeter prospects were identified to the north, east and west of Pitcairn prospect respectively. Later, these prospects were drilled and oil was found in the Angel Formation, proving to have commercial size of oil accumulation. Currently, detailed studies are being conducted toward the development of the Mutineer/Pitcairn/Norfolk complex and Exeter oil fields by the Joint Venture Partners.
So far, carbon dioxide emission reduction countermeasures to prevent global warming have been regarded as a large cost factor in the development of oil and natural gas in the oil development business. However, as concerns for global warming problem have risen, many international conferences have been held in the last ten years and scientific knowledge about the influence on the global environment due to mankind's economic activities has increased preventing global warming. The Kyoto Protocol was concluded as a result of such increased awareness. The countermeasures to control carbon dioxide reduction, which mean the various mechanisms in Kyoto Protocol, are emissions trading (Kyoto Protocol article of 17), joint implementation (JI) (Kyoto Protocol article of 6) and the foundation of clean development mechanism (CDM) (Kyoto Protocol article of 12). As a result, emission right credits have become available, and the possibility of new business opportunities to produce a profit by the oil development industries have arisen. It could be said that the CDM mechanism includes the possibility of changing the negative views previously held by the oil development industry towards carbon dioxide emission reduction. Instead of carbon dioxide emission reduction countermeasures being merely thought of as cost burdens, it is possible that the oil development industry will now realize new business opportunities.