International oil market until the early 2000s has been driven by two traditional factors: demand? supply fundamentals and geopolitical risk. In addition to these two traditional factors, money factors emerged as another driver for the oil market. During the oil price rise from 2004 to August 2007, fundamental and geopolitical risk factors played a major role while the inflow of speculative and investment money was increasing. From August 2007 to July 2008 when the oil price hit its highest at $147/bbl, money factor, instead of the traditional factors, became a major driving force behind the oil price increase. After the price peak in July 2008, all of three factors (fundamentals, geopolitical risk, and money) were not able to provide any reason for further price rise, and the oil price began to fall to adjust the overshooting until the price peak. The bankruptcy of Lehman Brothers in September 2008 then drastically changed the scene of oil market. It affected money factor in oil market through credit crunch. It also affected demand fundamentals through the overall economic downturn. Because of the sudden demand shrink, OPEC spare production capacity soared almost 5 million barrel per day in December 2008. This level is large enough to make market participants to feel less serious about supply crunch by geopolitical events. Indeed, geopolitical factor like the other two factors, no longer worked as a factor of oil price increase. Given the market fundamentals as well as the situation of international financial market, it is not likely that oil price sharply rises again in the short term. The average price of the second half of 2009 is forecasted at $60/bbl.
Russia, the largest gas producing country in the world, maintains investments not only in new gas field developments in Sakhalin, Yamal Peninsula and the Arctic but also in the gas pipeline network to the new markets in Northern and Southern Europe and the Far East to cope with their increasing demand. However, at the planning stage plans of cross-border gas pipelines are facing various types of competition. Russia confronts competition of gas suppliers, for example Turkmenistan for the market of China, on the other hand Russia made China a gas-market competitor against the traditional European market, which allowed Russia to win a series of long-term sales and purchase agreements from European gas distributors. As the gas demand soars, Russia may notch a stronger position against both East and West due to its magnitude and flexibility of deliveries,which is being accomplished not through geopolitics but rather through competition in the market.
About 20 years have been passed since Yufutsu Oil & Gas Field was discovered in 1988. After the first stage development until 1997, total 11 wells were drilled and Yufutsu Field has been producing oil and gas, due to several problematic producers and continuous rise of local demand for natural gas, however, JAPEX resumed the second stage development from the well “Numanohata SK-6D” in 2005 and total 6 wells have been drilled so far. At the first development stage, JAPEX encountered numbers of difficulties arising from formation properties, pressure and reservoir characteristics and overcame some, however there has been still existing some of these difficulties. At the second stage development, from new standpoint of well integrity which focuses on total well life and much stricter well conditions, cutting edge technologies and concepts have been applied in order to conquer these remaining difficulties and eventually achieved considerable results that include not only drilling but also both G & G and production phases. This paper addresses the basic direction of these achievements and further concerns for the development of the field.
INPEX is considering Reentry-drilling and completion campaign with 6″ hole in Minami-Nagaoka Green-Tuff reservoir. It is challenging to drill such a slim hole with tri-corn bit. In order to evaluate the applicability of fixed cutter bit, the first trial to drill 8-1/2″ hole in the Green-Tuff with fixed cutter bit and down hole motor was performed in Minami-Nagaoka well A. Two types of fixed cutter bit, PDC bit and Impregnated bit, were evaluated. The bit performances of these two bits were lower than tri-corn bit. Therefore, it can be concluded that tri-corn bit is suitable rather than these fixed cutter bits. However, when 6″ slim hole was drilled with tri-corn bit, severe bit damage and lower bit performance were found due to its low structural strength. From these points of view, it was concluded that especially with impregnated bit is better to be applied for drilling the slim hole in the field. To improve the performance of impregnated bit, it is essential to achieve higher rate of penetration and further extend the bit life. In this report, the applicability of high speed down hole motor with impregnated bit which has a small total flow area is studied and its hydraulics is calculated. As a result, it can be suggested that impregnated bit with high speed motor is suitable for drilling in the slim hole if limitations of rig capacity exists and both drilling and hole problems can be overcome.
CO2 resistant cement-zonal isolation technology dedicated to CO2 geological storage-provides an enduring solution to reducing well leakage risks in carbon capture and storage (CCS) and CO2 enhanced oil recovery (EOR) projects. CCS involves capturing CO2 from the major sources of concentrated emissions and injecting it into selected geological formations such as saline aquifers, depleted hydrocarbon reservoirs and unminable coal beds. CCS has the potential to make a critical contribution to reducing the amount of greenhouse gas released into the atmosphere as the most effective, safe, and low-cost long-term CO2 storage technology. One of the key requirements in CCS is long-term zonal isolation. Subsurface pressure and temperature changes can compromise the stability and integrity of the cement sheath around a CO2 injection well. Compromising well integrity can quickly lead to CO2 leakage at the surface, putting containment at risk. That's why the cement sheath used in the wellbore must be exceptionally durable and able to maintain its integrity for hundreds of years. Portland cement has been used successfully for decades in oil and gas well cementing. However, such cements are thermodynamically unstable in CO2-rich environments and degrade once exposed to CO2 in the presence of water. For this reason, compromised well integrity has been identified as the greatest risk factor for leakage from underground storage sites. CO2-resistant cement ensures lasting zonal isolation. In laboratory tests, the system proved highly resistant to CO2 attack, maintaining stable mechanical properties after exposure to simulated extreme injection/storage downhole conditions, including wet supercritical CO2 and water saturated with CO2. This cement system is 100% compatible with Portland cement and can be blended, mixed, and pumped using standard field equipment. It can be used for zonal isolation in new CO2 injection wells, or to plug and abandon existing CO2 injection/production wells at the end of a project.
INPEX Browse Ltd. has drilled 6 wells in the Browse Basin in order to appraise the production permit WA-285P from 2000 through 2004 (at the 1st and 2nd Drilling Campaign). All of wells have encountered stuck pipe problems while drilling the unconsolidated Grebe formation sandstone and they have provided a lot of Non Productive Time (NPT) due to fishing or sidetrack. According to the desk top study of Grebe, which was performed after drilling in 2004, it was concluded that the stuck pipe problems result from the collapse of unconsolidated sand, in other words, such collapse is caused by the absence of an effective filter cake capable of stabilizing the well bore. Eventually, INPEX Browse Ltd. has decided to drill the unconsolidated Grebe formation sandstone by closed circulation system using drilling mud instead of Seawater. In order to achieve this objective, Riserless Mud Return (RMR) system was introduced by AGR (Norwegian Company) before 3rd Drilling Campaign. Through this system, all three (3) wells have been successfully drilled without any hole collapse and no NPT was recorded. That is a major improvement rather than last two (2) drilling campaign and RMR system was demonstrated as one of an effective procedure to drill unconsolidated formation in Browse Basin.
Drilling fluid technology has been developing as a part of drilling technology to cope with a lot of problems facing with various kinds of drilling operations. In this paper, main functions of drilling fluid are reviewed, and the five issues below regarded as recent key technologies; 1) Hydration and swelling of shale, 2) Resistance to high temperature, 3) Highly deviated or horizontal drilling, 4) Ultra deep water drilling, and 5) Environmental responsibilities, which Telnite has been executing as Research and Development missions to date, are described.
Japan Drilling Co., Ltd. (JDC) owns and operates HAKURYU-5(H-5). It was built in 1977 at Mitsubishi Heavy Industries' Hiroshima Shipyard, and has been working over 30 years. To meet the requirements of the deepwater drilling demand, in 2004 JDC undertook a project that would extend the life and enhance the variable deck load (VDL) of H-5. Five engineering firms were invited to put forth proposals. EXMAR Offshore Company (EOC) was selected based on their remarkable ‘Deepdish’ concept. The Deepdish concept features transverse and diagonal braces formed as a unitized structure joined to the under side of lower hull. Basic design of Deepdish, including reinforcement of existing structure, was performed by EOC and approved by ABS Houston. Detailed design, made in January 2007, and fabrication of Deepdish was conducted by IHI Marine United (IHIMU). Deepdish was fabricated before the H-5 arrived at shipyard. Fabrication work of Deepdish began in March 2008 and was completed on October 14, 2008. H-5 arrived at IHI Aichi Works in Chita city on September 15, 2008 and docked in on October 20, 2008. Upon completion of dry-dock work, she docked out on February 7, 2009. The duration of dry-dock was three and half months, which is much shorter than conventional timeframes. The project was completed and H-5 sailed out on February 26, 2009 for operations offshore Vietnam. The key to the success of the project was to foresee potential problems and to prepare candidate solutions. These included, for example, strategies for minimizing the gap between the new and existing structures and maintaining the position control when mating the Deepdish to the H-5.
Our geochemical study on the gases from the Sagara oil field and its surrounding areas is summarized as follows. 1) The gases are of a thermogenic origin partly mixed with a small amount of microbial gas and are slightly biodegraded. 2) The δ13C1-δ13C2 plot of the gases shows that the maturity of the gases is estimated to be about 1.0% equivalent Ro and that the source rock for the gas from the MITI Omaezaki-oki well is different from the others. 3) The maturity of the Sagara oils estimated by light hydrocarbon and methylphenanthrene maturity parameters may be about the same as the maturity of the gases except for the Omaezaki-oki gas, which is more mature. 4) Geochemical characteristics of the oils and gases integrated with the results of the source rock analysis and the model simulation, reported by Ueda et al. (2007), indicates that the Sagara oils were probably generated in the Setogawa Group and migrated upward through the Ooigawa Group along faults. The Omaezaki-oki gas may be derived from the Mikura Group with long migration. The thermogenic gases absorbed in the Lower Miocene and older strata from the METI Nankai Trough well may be a mixture of gases generated in both the Mikura and Setogawa Groups.
Natural gas hydrates in sediment are expected to be developed as a resource of natural gas and have been studied as a possible future energy resource. Gas permeability and water permeability in the methane-hydrate (MH)-bearing sediments are important factors for estimating the efficiency of producing methane gas from the natural gas hydrate sediment. Permeability of MH-bearing sediment is considerably affected by several properties of sediment, i.e., pore-size distribution, porosity, cementing, MH saturation, and MH-bearing features. Glass beads sediment and sandy sediment with different grain sizes have been measured as fundamental research and for application to natural MH-bearing sediment. Sediment pore-size distribution and porosity have been measured by NMR and mercury porosimeter. In order to obtain pore-size distribution with higher spatial resolution, a technique of numerical conversion of NMR-T2 distribution have been developed. A semi-empirical (SE) equation of the permeability of glass beads and sandy sediment has been derived based on the Kozeny-Carman equation by pore-size distribution and porosity that had been measured by mercury porosimetry. This SE equation has been approximated by the relation of porosity, pore-size distribution, tortuosity, and specific surface area of the sediment. The SE equation has been applied for converted NMR-T2 distribution of MH-bearing sediment. The permeabilities of methane hydrate bearing sediment calculated by the SE equation correspond well to the permeability measured by water flow.
Depressurization method seems to be a cost-effective solution to liberate natural gas from methane hydrate-bearing layers. Depressurization decreases the system pressure to below the pressure of hydrate formation at a specific temperature. However the potential of producing gas from hydrate reservoirs has not been fully investigated. Therefore, a method of acquiring data from numerous dissociation experiments performed in a laboratory is necessary to assess the efficiency of the process and the decomposition characteristics. This research presents dissociation characteristics during depressurization. In our experiments, we used an artificial sedimentary core and performed several depressurization experiments under various depressurization rate and production pressure conditions. The temperature, pressure, and production volumes of gas and water were measured in response to time. As the results, production pressure affects gas recovery rate and production rate. Core sensible heat is rapidly consumed by dissociation and this heat is not supplied to dissociate all bearing methane hydrate.