Ultra-deep Drilling Research Articles

Experimental study of casing wear under impact-sliding conditions

Theoretical analysis and field monitoring show that lateral vibration has very important effect on casing wear in deep & ultra-deep well drilling. The wear mechanism of casing under impact-sliding work conditions has been investigated and many experiments have been completed with a newly developed full-scale casing wear test machine. Test results present that adhesion wear, contact fatigue, and grinding abrasion are the main wear mechanisms under impact-sliding test conditions. The friction coefficient and linear wear rate of the casing rise obviously with an increase in impact load. And the larger the impact load, the rougher the worn surface of the casing. The linear wear rate decreased slightly but the average friction coefficient increased slightly with an increase in impact frequency under an impact load of 2,500 N. Both the linear wear rate of the casing and the average friction coefficient increased substantially with an increase in impact frequency under an impact load of 4,000 N. Under lower impact load conditions, grinding abrasion and contact fatigue are the main mechanisms of casing wear; under higher impact load conditions, adhesion wear and contact fatigue are the main mechanisms of casing wear.

Japanese Association Promotes Upstream Technical Education

Editor's note: SPE seeks to develop strong relationships with other oil and gas societies worldwide. Many of these societies partner with SPE and other organizations on conferences, workshops, and other programs, at both the local and international levels. This series offers an overview of some of these societies. This installment in the series spotlights the Japanese Association for Petroleum Technology, known as JAPT. The Japanese Association for Petroleum Technology (JAPT), founded in 1933, sees its mission as one of collecting the latest technical and academic information pertaining to the exploration and development of hydrocarbon resources and disseminating that information to the oil industry. JAPT also provides a forum for the exchange of technical information among its members, promoting the multidisciplinary activities of geologists, geophysicists, and engineers. The association conducts meetings and workshops; publishes a journal, monographs, and books; recognizes industry excellence through awards; and exchanges information with related societies. Membership currently totals just under 1,700, with most members involved in the disciplines of exploration, production, and drilling. Membership is open to qualified individuals in the industry as well as to those in academia with a background in petroleum technology or science. Association member-ship is further divided into the categories of full member, emeritus member, student, honorary member, and corporate member. JAPT's flagship publication is the Journal of JAPT, which is published six times a year. It contains technical papers and commentaries in exploration and development and production, includes information about new technologies, and provides coverage of JAPT meetings and symposiums. Other publications of the association include monographs, glossaries, and reports by JAPT's technical committees on important issues. JAPT has published several books over the past 2 decades, including the Well Data Handbook, Exploration and Development of Hydrocarbon in Japan, Steel Tubes for Pipelines and Wells, Ultra-Deep Drilling, Drilling Manual, Guidelines on Safety and Environmental Protection Regulations, and Inclined Well Drilling Technology. JAPT annually recognizes excellence through its Distinguished Paper Award and its Distinguished Contribution Award. The association also conducts several meetings and workshops. Two large meetings take place—the annual Fall Meeting and the annual Spring Meeting. These include technical sessions and discussions on upstream topics, special presentations by both members and nonmembers, and joint seminars with other technical associations. Technical workshops cover exploration and drilling topics. Recent ones have covered sandstone formation, carbonate formation, geophysics, emerging technology, methane hydrate, and the association's drilling manual. JAPT has three standing technical committees, representing exploration, drilling, and reservoir and production. The committees promote the advancement of technology in their discipline, and exchange research with the other committees. JAPT and SPE have a longstanding relationship. JAPT has supported several SPE events in Japan, including three Applied Technology Workshops and the 2000 Asia Pacific Conference on Integrated Modeling for Asset Management. In addition, JAPT was an endorsing organization at the 2008 International Petroleum Technology Conference—which is organized by SPE and several other major societies—as well as the 2002 SPE International Conference on Health, Safety, and the Environment, both in Kuala Lumpur.

泥水技術の現状と課題

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.

NETL Extreme Drilling Laboratory Studies High Pressure High Temperature Drilling Phenomena

The U.S. Department of Energy’s National Energy Technology Laboratory (NETL) established the Extreme Drilling Laboratory to engineer effective and efficient drilling technologies viable at depths greater than 20,000 ft. This paper details the challenges of ultradeep drilling, documents reports of decreased drilling rates as a result of increasing fluid pressure and temperature, and describes NETL’s research and development activities. NETL is invested in laboratory-scale physical simulation. Its physical simulator will have capability of circulating drilling fluids at 30,000 psi and 480°F around a single drill cutter. This simulator is not yet operational; therefore, the results will be limited to the identification of leading hypotheses of drilling phenomena and NETL’s test plans to validate or refute such theories. Of particular interest to the Extreme Drilling Laboratory’s studies are the combinatorial effects of drilling fluid pressure, drilling fluid properties, rock properties, pore pressure, and drilling parameters, such as cutter rotational speed, weight on bit, and hydraulics associated with drilling fluid introduction to the rock-cutter interface. A detailed discussion of how each variable is controlled in a laboratory setting will be part of the conference paper and presentation.

Ultradeep Drilling Pushes Drillstring Technology Innovations

Summary Drilling ultradeep (UD) wells places significant requirements on the drillstring. Lengthy drillstrings lead to high tensile loads, which can lead to slip crushing of the drillstring; hoisting capacity issues; and drillpipe collapse capacity concerns at the blowout preventer (BOP). BOP shear rams may also have difficulty shearing today's high-strength, high-toughness drillpipe. Bottomhole assembly (BHA) connection failures pose greater risk and cost at UD well depths. This paper analyzes the many challenges associated with drill-string designs specifically for UD drilling (UDD). It presents emerging drillstring technologies that are solutions expected to increase depth capability for the industry's continued advancement of deep-drilling operations.

Drillstring Technology for World-Class Extended-Reach Drilling

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 18512, "Drillstring Technology Vanguard for World-Class Extended-Reach Drilling," by M.J. Jellison, SPE, and R.B. Chandler, SPE, Grant Prideco; M.L. Payne, SPE, BP; and J.S. Shepard, SPE, GlobalSantaFe, prepared for the 2007 Offshore Technology Conference, Houston, 30 April-3 May. Projects that will expand the extended-reach-drilling (ERD) envelope are in the planning stage in various parts of the world. Drilling engineers no longer are wondering if 50,000-ft ERD wells can be drilled but how this can be accomplished safely and efficiently. It has been estimated that the last 10% of the drilled interval can account for 50% of the total drilling cost. The full-length paper discusses the latest drillstring technologies that are essential to achieve the ERD targets planned for the future. Advanced Material Technologies Industry publications have presented the idea of using nonsteel drillstrings for reduction of torque and drag loads in extended-reach (ER) wells. Other torque- and drag-reduction and management tools and techniques that have proved successful are lower in cost, thus being the preferred methods for meeting current ER torque and drag challenges. The competition of these alternative technologies has inhibited the development of commercially available nonsteel drillpipe. The direction toward longer-departure ER wells has led to increased consideration recently for commercially available nonsteel drillpipe. Generally, three advanced materials should be included in this consideration—carbon-fiber-based composites, titanium, and aluminum. Each has been used in drillstrings with varying degrees of success. Each material has strengths and weaknesses relating to its use for drillpipe to drill ER wells and other critical applications such as ultradeep drilling and deep water. Carbon-Fiber-Based Composites. Composite drillpipe (CDP) is manufactured by winding carbon fibers over a mandrel while applying an epoxy matrix to encase the fibers and seal the assembly. CDP manufactured to date has had steel pin-and-box tool joints similar in design to conventional steel-drillpipe connections. The steel tool joints are attached to the composite tube during the winding process in which the carbon fibers are placed over specially designed ends of the tool-joint members to bond with the composite tube and resist fatigue in service. Currently produced CDP is approximately three times the cost of conventional steel drillpipe. As the technology improves and the capabilities of carbon-fiber manufacturers advance, this price differential may decrease. CDP offers several potential advantages over conventional steel drillpipe that could make CDP particularly well suited to ERD and other critical drilling applications.

Overview: Drilling Technology (February 2008)

Overview An increasing number of superlatives are used to describe challenges that the drilling industry faces. Indeed, adjectives such as high, extreme, long, ultra, severe, or extra are used quite often to qualify the complexity of wells drilled today or that will be drilled in the near future. To name a few, one hears about ultradeep offshore, ultradeep drilling, ultraslim tools, very-extended-reach drilling, high-rate data transmission, ultrahigh torque connections, ultrahigh-strength steel, high-accuracy measurement, very advanced modeling, high-definition visualization, high-performance, and many others. Drilling becomes less and less conventional in terms of materials, techniques, data acquisition, and transmission systems and turns into unconventional or extreme drilling by use of new technologies and operating limits. Another observation is that the drilling industry attempts to combine and integrate several drilling techniques and methods, not only to overcome the difficulty and complexity of drilling deeper, longer, and in higher pressure and temperature in a severe downhole environment, but also to extend the production of mature or depleted fields. For example, it is not rare to combine coiled-tubing drilling with underbalanced-drilling methods, or an ultraslim rotary-steerable system with a casing-while-drilling (CWD) system. There is talk about combining CWD technology with expandable tubulars. In brief, complex-drilling challenges will find their economic and engineering solutions by mixing several high-level technologies. Papers presented on the following pages and in the additional reading illustrate these technology trends.Ultradeep or extra-long drilling requires increasingly higher-strength drillpipe and advancements in material to reach the target successfully and safely.Drilling technology must be accompanied with realistic and advanced modeling or laboratory experiments to obtain better benefit from and understanding of complex hydraulic and mechanical phenomena.New managed-pressure-drilling methods are required to compensate dynamic pressure in reservoirs having a low margin between the fracture- and the pore-pressure gradients. Drilling Technology additional reading available at the SPE eLibrary: www.spe.org SPE 110708 "Case Study: Drillstring-Failure Analysis and New Deep-Well Guidelines Lead to Success" by David R. Bert, SPE, BP plc, et al. SPE 107903 "Implementation of a Shock- and Vibration-Mitigation Process: Achieving Real-Time Solutions and Savings" by Goke Akinniranye, SPE, Schlumberger, et al. SPE 107547 "Improved Drilling-Process Control Through Continuous Particle and Cuttings Monitoring" by T.H. Omland, Statoil, et al. SPE 109530 "The Extraction of Mud-Stuck Tubulars Using Vibratory Resonant Techniques" by Ozzie Gonzalez, Vibration Technology, et al.

モホの岩石学的実体を探る

This article reviews interpretations of the geological and petrological nature of the Moho, which is defined as a discontinuity in terms of Vp, with a view to preparing for the Mohole on the ocean floor in IODP. We strongly propose discarding non-seismic terms for the Moho, such as “petrologic Moho”. The nature of the Moho has been controversial for a long time; an isochemical phase transition boundary between gabbro (crust) and eclogite (mantle) was favored for the Moho by some researchers, while a chemical boundary between mafic rocks (crust) and peridotite rocks (upper mantle) is now favored by a majority of researchers. Boundaries between completely or partially serpentinized peridotite and fresh peridotite may be applicable as the Moho at some parts of the ocean floors of a slow-spreading ridge origin. Antigorite serpentinite can be expected to be observed at the lowermost crust if the Moho is the serpentinization front at the stability limit of serpentine. The Moho beneath the Japan arcs can be estimated using mafic-ultramafic xenoliths in Cenozoic volcanics. Peridotitic rocks scarcely mix with feldspathic rocks, indicating that the Moho at that location is the boundary between feldspathic rocks (mostly mafic granulites; crust) and spinel pyroxenites (mantle). Possible fossil Mohos are observed in well-preserved ophiolites, such as the Oman ophiolite. Two types of Moho are distinct in the Oman ophiolite; gabbro-in-dunite Moho, where a gabbro band network in dunite changes upward to the layered gabbro within a few to several tens of meters, and dunite-in-gabbro Moho, where late-intrusive dunites intruded into gabbros. The former is of a primary origin at a fast-spreading ridge, and the latter is of a secondary origin at a subduction-zone setting in the obduction of the oceanic lithosphere as an ophiolite. The gabbro/peridotite (dunite) boundary as the primary Moho forms in embryo as a wall of melt conduit at fast-spreading ridges as well as at the segment center of slow-spreading ridges. The oceanic primary Moho is modified to various degrees by magmatism, metamorphism and tectonism in subsequent arc and continental environments. The gabbro-in-dunite Moho formation in the Oman ophiolite is an embryo of this modification. We expect in-situ sampling across the primary oceanic Moho formed at a fast-spreading ridge through the Mohole of IODP. Ultra-deep drilling at gabbro/peridotite complexes exposed on the ocean floor is indispensable for our understanding of the suboceanic upper mantle. Studies on appropriate ophiolites and deep-seated xenoliths from oceanic areas should complement the Mohole and other ultra-deep drillings to grasp the whole picture of the oceanic upper mantle.

Nanosecond-laser plasma-assisted ultradeep microdrilling of optically opaque and transparent solids

A mechanism of ultradeep (up to tens of microns per pulse, submillimeter total hole depths) plasma-assisted ablative drilling of optically opaque and transparent materials by high-power nanosecond lasers has been proposed and verified experimentally using optical transmission and contact photoacoustic techniques to measure average drilling rates per laser shot versus laser intensity at constant focusing conditions. The plots of average drilling rates versus laser intensity exhibit slopes which are in good agreement with those predicted by the proposed model and also with other experimental studies. The proposed ultradeep drilling mechanism consists of a number of stages, including ultradeep “nonthermal” energy delivery into bulk solids by the short-wavelength radiation of the hot ablative plasma, bulk heating and melting, accompanied by subsurface boiling in the melt pool, and resulting melt expulsion from the target.

Guest Editorial: Upstream Business of the Future: Funneling Changes Everything

While the "digital oil field of the future" is generating lots of excitement, this enthusiasm should not dominate the industry's thinking about the real upstream business of the future. But it is, and it is time that this changed. Although nobody knows exactly what the upstream business of the future will look like, shaping forces are already in motion. In addition to the digital oil field's bright lights, shaping forces are coming from three other innovation areas or fronts: conventional technologies, management disciplines, and technologies from the manufacturing industry, with technology defined as any know-how vital to a business. The latter includes hardware and software. The business problem is that innovation areas outside of conventional technologies typically do not receive their fair share of attention or funding. What is needed is a single, big "funnel" through which all technologies sift, allowing operators and service providers to choose the most promising ones based on merit rather than the newest fad, conventional wisdom, or long-followed business practices. Balance is the key. It is not surprising that conventional technologies get the lion's share of R&D money because conventional technology has produced a wealth of new E&P techniques over the years. Those technologies have dramatically helped companies find hydrocarbons more easily and cheaply, as well as produce them more efficiently and in greater volume than ever before. Horizontal drilling is a prime example. Look more closely at three innovation fronts other than conventional technologies. One promising front is the aforementioned digital oil field of the future, also called the e-field or even "drilling on the computer." It is defined as the application of information technologies and computer applications to the various upstream operations. The automated oil field might enable an individual at headquarters to monitor production wells, open and close valves, and determine when it is time for certain wellsite operations. Or it may be remotely controlled actuator valves or wireless communications with handheld devices that make invoicing obsolete. The digital oil field is a seemingly endless innovation generator. But equally significant is the adoption of best practices and proven technologies from what amounts to a revolutionized field of manufacturing techniques that could produce increased savings and higher productivity in upstream operations. Examples include flexible manufacturing techniques that have made ultradeep offshore drilling attractive to independents, process improvement techniques that reduce downtime on rigs, and work process standardization for drilling operations that allows continuing improvement in performance and reduction of human errors. The third innovation area outside of conventional technologies—management disciplines—focuses on more robust project and program management. Certainly, capital projects have been project managed in the oil and gas industry for decades. But at what "real" cost? Studies show that less than 5% of all projects actually meet project managers' key objectives such as being on time and on budget. That clearly needs major improvement, and it will be necessary to shift from informal project management "on the back of an envelope" to a more disciplined approach of managing projects with their inherent risks.

Quaternary turbidite systems on the northern margins of the Balearic Basin (Western Mediterranean): a synthesis

The Balearic Basin is a young basin composed of thick Plio–Quaternary sediments, including active gravity sedimentation. During the Quaternary, gravity processes deposited (1) turbidite systems, either as symmetrical fans (Petit-Rhone and Valencia fans) or asymmetrical ridges (Marseille–Planier, Grand-Rhone and Pyreneo-Languedocian ridges) and (2) several mass-transport deposits, indicating recurrent sedimentary failures of the margin. This paper synthesizes previous works and proposes a chronological sedimentary evolution for the basin. Except for the last 20 ka, the chronostratigraphy remains poorly constrained but should soon be established for the last 500 ka, based on the PROMESS1 drillings on the outer shelf of the Gulf of Lions, and hopefully for the last 30 Ma, based on ultra-deep drilling in the deep basin from aboard the Chikyu research vessel (IODP proposal Pre699).

Measurement and modeling of methane dissolution in synthetic liquids applied to drilling fluid formulation for deep and ultradeep water wells

Most of the Brazilian oil and gas reserves are located in offshore fields. There is also a great production potential in offshore reservoirs in deep and ultradeep water depths. The drilling scenario at those depths is quite complex and the risk of blowouts should be mitigated. A well control problem would incur in loss of human lives, equipment and catastrophic environmental damages. In order to overcome technical and environmental restrictions, synthetic liquids have been applied in the formulation of drilling fluids. Synthetic based drilling fluids show excellent lubricity and shale stabilization characteristics and may be the only option when drilling in high temperature and high pressure environments. The better understanding of the interaction between formation gas and a synthetic based drilling fluid during a kick detection and circulation situation would contribute to safely and economically drill the offshore wells. The present work involves PVT measurements and thermodynamic modeling of three mixtures of methane and organic liquids (n-paraffin, ester and a iso-paraffin : n-paraffin mixture), currently applied in drilling fluid systems for deep and ultradeep water drilling, in Campos Basin (Rio de Janeiro, Brazil). The measurement of thermodynamic properties of the methane–liquid mixtures, such as bubble point pressure, solubility, oil formation volume factor, gas formation volume factor and liquid density, were performed for 70 and 90 °C temperatures. The measurements were conducted in two different apparatuses: an Hg system and an Hg-free PVT system. The thermodynamic modeling of the gas–liquid system was based on Krichevsky–Kasarnovsky correction of Henry's law. The results showed that the precise accounting of formation gas solubility in the fluid under downhole conditions and during the kick circulation is a very important issue for safely drill deep and ultradeep water wells.

Ultra Deep Water Drilling Riser Design and Relative Technology

IFP has developed tools and technology to answer the waiting of contractors that wish to drill in deeper water depths, in harsher environment with higher mud weight. The methodology aims to optimise the riser design by proposing practical guidelines implemented by a software. To reduce unproductive time on the rig during the drilling, the Clip Riser has been developed. The main feature of the Clip Riser is the coupling which allows quick make-up of the riser. The clip technology is a unique design which does not require bolts, threads or any preloading in operation. To reduce drillship deckload and required tensioning capacity, the hybrid tubes have been developed to replace the existing 4 1/2 ID (114. 3 mm) steel kill and choke lines by lighter tubes. The hybrid tubes are 50% lighter than equivalent all steel lines. Advantages of this technology will be presented in this paper. To improve axial behavior of the riser and riser architecture, hyperstatic integration of choke and kill lines have been studied. This consists in fixing the auxiliary lines at each riser joint so that they can participate to the axial resistance of the riser. Advantages of this system will be presented in this paper. Finally, the technological developments should answer the waiting of contractors and will further expand the range of application of standard riser systems and make them well suited for ultra deep drilling in very harsh operational and oceanographic environments.

ABSTRACT: An Integrated Analysis of the Madison Formation: Madden Field, Fremont County, Wyoming

Abstract The ultra deep and ultra expensive drilling occurring in the Madden field of the Wind River basin commands a lot of preparation and analysis. This 25,000-foot reservoir possesses multiple trillion cubic feet capabilities from no less than four wellbores to as many as 11. Daily production rates per wellbore range from 40 to 50 MMCF. These rates are constrained due to processing capacity. Wells are capable of substantially higher rates since calculated Absolute Open Flows of more than 150 MMCF have been recorded. The gas being produced is extremely sour and dirty. The hydrogen sulfide content hovers around 12% and is coupled with a carbon dioxide content of 21%. This leaves a hydrocarbon content of only 67%, which is basically all methane. Expensive gas plant facilities are required to treat and process this gas. The current daily inlet volume is 130 MMCF but construction is underway to increase this to 310 MMCF at a cost of about 1.5 MM$ per million cubic feet. The productive reservoir is fractured, dolomitized limestone situated on an immense structural closure. The structural closure is bounded on all sides by thrust faults with vertical displacements as high as 5,000'. A gas column at least 1,200' thick has been proven. The justification of this project has been achieved through thorough investigation of the geology, geophysics, and reservoir engineering. The latest technologies have been employed to maximize success. Risk analysis, reservoir simulation, three dimensional seismic interpretation, core analysis, outcrop analysis, and subsurface e-log analysis are the tools that have been utilized to generate a collective evaluation of this world class gas reserve.

ＪＵＤＧＥ井（１０ｋｍ，４００℃）掘削の困難性と実現に向けての基本戦略の提案

Japanese Ultra-deep Drilling and Geo-scientific Experiments (JUDGE), which aim to drill into the Philippine-Sea-Plate subduction zone from the Japanese Island, had been proposed by scientists more than ten years ago. Scientists estimate the plate can be reached with a 10-km deep borehole, and they predict that the formation temperature will increase from 200 to 400°C at that depth. Some studies were made about this project several years ago, however, no drilling proposal has been submitted to conduct this project.This paper discusses: What are the major technical issues to carry out this project? How deep can we drill into the formation with estimated formation temperature gradients?, and How should we plan this project? Numerical simulations were conducted to find out the temperature changes in the borehole during drilling operations. The results are: A 7-km hole can be drilled, but the 10km hole will be very difficult to drill with conventional drilling methods and existing muds and tools.Based on simulation results a 12-year project plan, consisting of 3-phases, was proposed. Phase-1 is 5 years and assigned to be a planning and engineering stage. A 6-km to 7-km hole was planned to determine actual formation temperature and bore hole stabilities. Based on the obtained information, necessary research will be conducted in phase-2. To test the temperature capabilities of drilling and logging tools, a 4km-deep high-temperature well will be drilled in a geothermal area. Phase-3 is the execution stage to drill the 10-km well in four years.Temperature simulation results showed that it would be very difficult to drill 10km-JUDGE well with conventional method, however new drilling methods such as casing-drilling, expandable-tube, TDS-cooling-method etc., have been developed recently. So, it seems that the JUDGE project is no longer just a scientists' dream, but could be feasible in the near future.

Was the 1999 Chi-Chi Earthquake in Taiwan a ""Subduction Earthquake""?

Based on paleo-reconstructions of tectonic evolution of Taiwan, on the style of deformation across the Taiwan mountain ranges, on global travel-time tomography beneath Taiwan and on the characteristics of the Chi-Chi earthquake, I propose that the last M7.6 earthquake is a “subduction earthquake” which has ruptured a segment of the plate interface between the Eurasia and the Philippine Sea. Considering this event as an interface thrust earthquake, I propose to guide the future investigations of the Taiwan Foothills with such view including ultra-deep drilling (about 5-8 km) through the ruptured fault, down-hole permanent monitoring, systematic paleoseismic studies across active faults and numerical modeling of elastic deformation of Taiwan coupled with GPS observations. The aim of these studies being the determination of the distribution, recurrence and magnitudes of earthquakes in the western part of Taiwan.

5707939 Silicone oil-based drilling fluids

Most of the Brazilian oil and gas reserves are located in offshore fields. There is also a great production potential in offshore reservoirs in deep and ultradeep water depths. The drilling scenario at those depths is quite complex and the risk of blowouts should be mitigated. A well control problem would incur in loss of human lives, equipment and catastrophic environmental damages. In order to overcome technical and environmental restrictions, synthetic liquids have been applied in the formulation of drilling fluids. Synthetic based drilling fluids show excellent lubricity and shale stabilization characteristics and may be the only option when drilling in high temperature and high pressure environments. The better understanding of the interaction between formation gas and a synthetic based drilling fluid during a kick detection and circulation situation would contribute to safely and economically drill the offshore wells. The present work involves PVT measurements and thermodynamic modeling of three mixtures of methane and organic liquids (n-paraffin, ester and a iso-paraffin : n-paraffin mixture), currently applied in drilling fluid systems for deep and ultradeep water drilling, in Campos Basin (Rio de Janeiro, Brazil). The measurement of thermodynamic properties of the methane–liquid mixtures, such as bubble point pressure, solubility, oil formation volume factor, gas formation volume factor and liquid density, were performed for 70 and 90 °C temperatures. The measurements were conducted in two different apparatuses: an Hg system and an Hg-free PVT system. The thermodynamic modeling of the gas–liquid system was based on Krichevsky–Kasarnovsky correction of Henry's law. The results showed that the precise accounting of formation gas solubility in the fluid under downhole conditions and during the kick circulation is a very important issue for safely drill deep and ultradeep water wells.

超深度ボーリングJUDGE計画

超深度ボーリングJUDGE計画

Petrophysical features of the ore-bearing Eldzhurtinsky massif (northern Caucasus)

The Eldzhurtinsky granite massif was formed during the Late Alpine tectono-magmatic activity. The molybdenum-tungsten deposit is associated with it spatially and paragenetically. Under the ultradeep drilling programme, wells to a depth of 4695 m are drilled into the massif. Comprehensive petrophysical studies were conducted on the basis of cores from four of the wells; the vertical (No. 600, 104, 1500) and horizontal (No. 1393) have made it possible to reveal the petrophysical characteristics of the intrusion in the vertical plan in the 3300 × 1100 m cross-section. Altogether, 72 samples have been studied. In keeping with the technique worked out at the Geological Faculty of Moscow University, the following properties were determined: density, porosity, saturation parameters and elastic parameters; and velocities of longitudinal and transverse ultrasound waves, Poisson coefficients, shear and Young's moduli and piezoelectric characteristics. Debye temperature and the comprehensive petrophysical coefficient were calculated. Petrophysical zonality was detected in the vertical cross-section of the massif in the direction from top to bottom. From the physical-mechanical properties and the character of multi-dimensional correlation between various properties, the investigated cross-section of the massif can be divided into three zones: the upper, the middle and the lower.

Seismic evidence of increased tectonothermal activity near the Oberpfalz deep continental drilling location (SE Germany)

The success of ultradeep drilling projects, as e.g. within the German Continental Deep Drilling Programme (Kontinentales Tiefbohrprogramm, KTB) in the Oberpfalz strongly depends on the thermal and geological-tectonic environment of the well. In the present paper we apply the correlation of elevated temperatures and seismic reflectivity of the lower continental crust to the deep seismic network of the Oberpfalz. The results together with the correlation to other geoscientific data indicate increased temperatures in the area of the KTB location. These temperatures are most probably related to influences of the Eger graben and possibly are not yet measured at the surface using heat flow determinations.