The Yufutsu Gas Field underlying in depths more than 4, 000 meters, locates in the vicinity of the Tomakomai industrial area, 50km south of Sapporo-city in Hokkaido, Japan. The field was discovered by the exploratory well “Minami-Yufutsu SK-1” in 1988 after years of exploiting activities of JAPEX. Exploration drilling in the southern part of Hokkaido had been continually carried out by JAPEX since 1961, in an attempt to find a promising hydrocarbon accumulation in the area. These efforts had, however, resulted in failure before the Minami-Yufutsu SK-1 well, because of production capability of each well that was not assessed to be commercially viable. Subsequent to the successful result in the Minami-Yufutsu well, a series of delineation wells was drilled, disclosing the essential information to evaluate the reservoir, and encouraging us to take further steps towards its development. Following an intensive study of examining the field from both technical and economic points of view, its development was officially announced in 1993. Production began in early 1996, supplying clean energy of natural gas to the local community. This field is quite distinctive among other gas fields worldwide in its type of reservoir formations, which are in combination of naturally fractured granite and conglomerate. Due to the type of reservoir formations, the depths underlying, and the reservoir fluids properties, that contain waxy oil of its pour point indicating 82°F, there were a number of difficulties in designing and executing both well construction and well completion operations. This report gives an overview of the technologies/solutions applied to develop the field during the past decade, and will help us foresee our business circumstances in the next decade.
This paper addresses several of the recent developments and implementations in the drilling equipment and related system to overcome the adversities associated with the harsh environment of extreme water depths. Also, this paper presents a few of the dynamically positioned system such as a DPS class, thruster power/design and a reliability. West Future II, which is under construction in Ariake Works of Hitachi Zosen ordered by Smedvig, is an example of rig construction for deep water drilling. This paper also presents the unique features of RamRig that will be installed on the West Future II.
Recently, we are facing difficulties of drilling and well service operations with conventional drilling rig inland of Japan. These are mainly the difficulty of getting enough location area and preventing environmental noise pollution due to the expansion of residence areas or industrial areas. And more cost reduction of personnel expense is getting forced because of the cost increase with regard to environmental concerns. Teikoku Oil Co., Ltd. purchased a new semi-automatic compact electrical powered drilling rig to overcome the problems above mentioned. In this paper, we would like to introduce the great advantages and the superior characteristics of the new rig. Its characteristics are as follows: •safe operation by automatic operational system •requires less operational personnel •compact size for limited operational space •quiet operation by electric power supplying system Since its introduction last September (1997), it has successfully drilled four wells in Chiba prefecture, which contributes to the production of natural gas dissolved in water.
In Abu Dhabi marine area, the first horizontal well was drilled from one of the existing wells in 1989. Since then, 168 horizontal wells have been drilled by the end of 1997. The horizontal wells are commonly applied in all the developing fields by drilling new wells as well as re-entry wells. This report reviews the progress of horizontal drilling techniques in the last nine years. Our horizontal drilling is categorized into four phases where different drilling/completion techniques were applied, namely single horizontal wells with single completion, single horizontal wells with dual completion, dual lateral horizontal wells and multi lateral horizontal wells. The change from one phase to the next took place owing to the improvement of drilling methods and availability of the new tools. The feature of these methods and tools are also described with field experiences.
There are three technical innovations related to drilling fluids technology in this decade in Japan. Two of them are developments of the ultra high temperature water-based mud system and the extremely high lubricity water-based mud system. These two water-based mud systems had given big contribution to the drilling of ultra-deep high temperature, high pressure wells and horizontal, extended reach wells. Third innovation is the development of new waste mud disposal treatment system with using distillation technology. Much waste volume could be reduced by this new treatment system in oil field. Developments and actual field trials of these three new innovated systems are described in this paper, and also further break-through related to drilling fluid is described.
Pipe management is one of the key elements of coiled tubing operation. Durability of the coiled tubing was simply evaluated by running feet for a long period of time which resulted in tubing failure. After extensive testing at the research facility, we obtained a reliable model to estimate coiled tubing fatigue. Now we have introduced a PC-based pipe management system called “CoilCAT” which eliminates extensive manual recording during operation. It also improves safety, economics and reliability. CoilCAT consists of a sensor network and a PC which acquires and analyzes they data. During operation, circulating pressure, well head pressure, coiled tubing weight, running speed, depth, coiled tubing dimension, and other data are monitored and collected with the history of the tubing already in the PC. At the same time, it will display pressure and tension limits of that particular condition. The system can alert the operator if any of the monitored and calculated values exceed the predetermined limits.
Drilling Technology in the oil industry is the technology required to drill wells for exploration and production of oil and gas resources. JNOC-TRC's Drilling and Completion Lab. is engaged in research and development (R & D) with three main goals: drilling cost reduction, drilling in challenging frontiers and environmental safety in drilling. This R & D effort also covers the well completion technology needed to produce oil and gas from the wells drilled. R & D has been carried out to date under the three pillars of basic research, large-scale research and specific (applied) research. Recent trends in R & D including horizontal well technology, slim-hole drilling technology and methane hydrate technology will be introduced here.
In MEOR field operations, injection of microorganism (s) may cause the competition between the injected microorganism and natural microorganisms in the reservoir, which may lead to unexpected results. Therefore, utilization of natural microorganisms in the reservoir for MEOR may be one of the best solution. In the present study, first of all, natural microorganisms were collected from the reservoir brine of six production wells in the target oil field, and 32 bacteria were isolated. Then, their function for MEOR were tested, and it was found that No. 12 strain produced a large amount of CO2 gas and metabolites of ethanol and acetic acid, and addition of a small amount of (NH4)2HPO4 increased the production of CO2. Huff and Puff field trials with No. 12 strain Jilin oil field, China were carried out for four wells in 1997. As a result, it was found that the oil production rate increased by 46.4% on the average of four wells for 70 day production, due to the increase of rate of production fluid, not the increase of oil cut.
To establish the bioremediation process for marine oil spill, it is necessary to know microbial reaction for degrading individual hydrocarbons. Petroleum hydrocarbons are generally ranked in the following order of susceptibility to microbial attack : n-alkanes>low molecular-weight aromatics>cyclic alkanes>asphaltenes and resins. This part describes metabolic pathways of n-alkanes and aromatic hydrocarbons in detail.
The SPE-JAPT-JNOC Applied Technology Workshop, held on 5-8 April 1998 in Chiba, was attended by 64 multidisciplinary professionals, representing 27 companies and 5 universities from 12 countries. This intense and focused two and a half days workshop provided an excellent opportunity for participants to share their experiences and ideas, both through presentation of case studies and subsequent discussions, and to practice a multidisciplinary team approach in syndicate sessions. Participants had indicated their expectations of workshop, confirming among others two key interests: reservoir characterization and subsurface uncertainties. Technical sessions were tailored to meet those expectations, including the goals and objectives of the SPE ATW. The technical agenda was arranged to cover key elements of technology for field development planning.