ALBERT

Description: Casten, U.: Gravimetrie in der KTB-Pilotbohrung. p. 23-39. Bosum, W., Geipel, H.: TFM (Triaxial Fluxgate Magnetometer) - Messungen in der KTB-Oberpfalz VB von 1180 m bis 2750 m. Meßergebnisse und erste Interpretation. p. 43-69. Kuhnke, F., Musmann, G.: KTB-Hochtemperatur Drei-Komponenten-Magnetometer. p. 71-109. Ponomarey, V. N., Gluhih, I. I., Astrahancev, J. G., Badjin, G. W.: Magnetometrische Untersuchungen in der Kontinentalen Tiefbohrung KTB-Oberpfalz VB. p. 111-114. Bram, K.: Vorbereitung und Durchführung von Magnetikmessungen in der KTB-Oberpfalz VB durch das Institut für Geophysik, Sverdlovsk, UdSSR. p. 115-118. Krammer, K., Pohl, J.: Das Suszeptibilitätslog der Bohrung KTB-Oberpfalz VB von 27 m bis 3980 m. p. 119-134. Steveling, E., Spitzer, K., Leven, M.: Messungen mit dem Göttinger Bohrlochmagnetometer zur vertikalen Gradientensondierung in der KTB-Oberpfalz VB. p. 135-156. Grinat, M.: Messungen der Induzierten Polarisation in der KTB-Oberpfalz VB. p. 205-206. Winter, H., Stoll, J., Aulbach, E.: Die neue Eigenpotential-Bohrlochsonde - Erste Ergebnisse in der KTB-Oberpfalz VB. p. 159-177. Bahr, K., Eisel, M.: Vertikale tellurische Pulsationen in der KTB-Vorbohrung: Laterale Leitfähigkeitskontraste und virtuelle zeitliche Variationen des Eigenpotentials. p. 179-189. Grinat, M.: Messungen der induzierten Polarisation. p. 191-204. Schepers, R.: FACSIMILE - A new acoustic borehole imaging tool. p. 209-222. NN: Variable Acoustic Low Frequency System (VAL) der Firma Petrodata, Zürich. p. 223-226. Jobmann, M.: Thermischer Injektionstest und Temperaturmessung nach sechsmonatiger Standzeit in der KTB-Oberpfalz VB. p. 229-243. Burkhardt, H., Honarmand, H., Pribnow, D.: First results of thermal conductivity measurements with a borehole tool for great depths. p. 245-258. Stiefel, A.: Gegenstrom-Wärmetauscher-Experiment und Temperaturangleich in der KTB-Oberpfalz VB vom 09. bis 19. März 1990. p. 259-281. Reifenstahl, F., Stober, I.: Absenk-/Injektionstests und Leitfähigkeits-Fluid-Logging in der KTB-Oberpfalz VB. p. 285-313. Kessels, W.: Zielsetzung und Durchführung hydraulischer Untersuchungen in der Bohrung KTB-Oberpfalz VB im Langzeitmeß- und Testprogramm. p. 315-339. Zoth, G.: Erprobung eines Multifluidsamplers (Prototyp) der Firma Schlumberger. p. 341-342. Zoth, G.: Test des LASL-Fluidprobennehmers im Hinblick auf den Einsatz in der Hauptbohrung. p. 343-350. Baumgärtner, J., Rummel, F., Zoback, M. D.: Hydraulic Fracturing in situ Stress Measurements to 3 km Depth in the KTB Pilot Hole VB. A Summary of a preliminary data evaluation. p. 353-399. Heinemann, B., Mastin, l., Fuchs, K., Zoback, M.: Auswertungen der Bohrlochgeometriedaten der KTB Vorbohrung von 500 bis 4000 m Tiefe; Analyse der Breakout-Orientierungen im Hinblick auf das herrschende Spannungsfeld. p. 401-431. Zoth, G.: Test des 6-Arm Kalibermeßgerätes (Prototyp). p. 433-436. NN: Das Mechanical Sidewall Coredriller Tool der Fa. Schlumberger. p. 437. Schweitzer, J., Peterson, C.A.: Logging with a Germanium Spectrometer. p. 441-449. Draxler, J.: Preparation and operation of the prototype Germanium Detector Tool from Schlumberger-Doll Research, Ridgefield, Conneticut, USA. p. 451-458.

Description: During the 3D seismic reflection survey within the project Integrated Seisrnics Oberpfalz 1989 (ISO89) the vibroseis source signals were recorded simultaneously with five threecomponent geophone borehole chain SEKANS or a single threecomponent borehole geophone, respectively, in the KTB pilot hole. The aim was to measure the traveltimes of direct waves in the depth range between 3220 and 3420 m in order to deduce spatial velocity inhomogeneities between surface and recording depth from traveltime residuals in the surroundings of the KTB. These data shall be used for improved static corrections if distinct from statics obtained by short refraction lines and first arrival analysis of surface data. A short description of the method is given which is based on approximation by least square fitted planes. Data examples and preliminary results are presented.

Description: The tool chain SEKAN 5 developed and constructed by PRAKLASEISMOS was proved to be capable of withstanding long-term operation under the given pressure and temperature conditions in a chemically active Dehydrill HT mud in the KTB Oberpfalz VB lA (350 bar, 110 °C, pH 10-11). The tool comprises five identical seismic receiver sondes which are equipped with a three-component receiver system, an electrically driven clamping unit and a magnetic compass system. The results of the reference tests and the measured compass values were subjected to critical checks. For the observation period the reference tests on different days for each individual sonde indicated good agreement with respect to specific signal forms. The differences in orientation determined from the seismic data and the compass values are between -11 degrees and -26 degrees. The cause of the differences can be explained in that the wave paths lie outside of the observation plane.

Description: The high reflectivity of the upper and middle crust of the Oberpfalz, both for near vertical and wide-angle reflections, was one reason for selecting this area as site for the German Continental Deep Drilling Program KTB. A peculiarity in the middle crust beneath the KTB site is the so-called Erbendorf-Body (EB) giving rise to extremely strong wide-angle reflections. It deserves special interest because its position right on the border between the Saxothuringian and Moldanubian zones of the Vari scan fold belt, the unusual high p-wave velocities (over 7.0 km/s) in its lower part at 11 to 14 km depth, and associated dipping reflectors suggest a possible lower crustal origin of the EB. A specially designed and so far unique wide-angle 3D-survey was carried out as part of the program "Integrated Seismics Oberpfalz 89" for investigating the spatial extent, the velocity distribution and the internal structure of the EB. The first results show clearly that the EB ist not a local phenomenon beneath the DEKORP4 line, but that it exists, yet with remarkable complexities, beneath the whole covered area between the Franconian Line and the Falkenberg granite complex. The wide-angle shots were also recorded by four 3-component geophones in the KTB pilot hole at 3195 to 3295 m depth and provided convincing evidence for s-wave splitting in the upper crust SE of the KTB location. This anisotropy effect seems to be related to the overall strike and dip of rock foliation in the zone of Erbendorf-VohenstrauB (ZEV).

Description: Data are presented from integrated special experiments which have been performed in conjunction with a seismic 30 reflection survey within the framework of IS089 ( Integrated Sei smi cs Oberpfal z 1989) coordinated by DEKOR(PG erman Continental Seismic Reflection Program) between July and Novembero f 1989. The main objective was to study the nature of P- and S-wave reflections and velocities, the Poisson's ratio and the seismic anisotropy in a medium of crystalline rocks around the KTB site (Continental Deep Drilling Program), where the borehole has reached a depth of 4000 m. A digital 5-unit geophone chain with 25 m spacing and three components was used for downhole recording. The program described here consists of: 1) shearwave 2D reflection profiling (SCMPw} ith two 10-12 km long lines crossing the KTB-site, source: 2 horizontal vibrators with different orientations, 3-component recording; 2) shearwave moving source profiling (S-MSP); downhole recording of the source points of the SCMP; 3) vertical seismic profiling (VSP) down to 3660 m with different source azimuths and offsets (zero-offset, 4 km, 8 km); P- and S-wave sources: explosives, horizontal and vertical vibrators, and horizontal hammer techniques. 4) multiple azimuth shearwave experiment (MASE) with 4 km and 8 km offset and horizontal vibrator sources (radial and transversal orientation). The VSP surveys display steeply dipping reflections, increasing in number below 3000 m depth. Horizontal structures, preferentially seen in the surface profiling, are the exception. Polarization analysis of shearwaves shows dominant azimuths in shearwave splitting which correlate with maximum horizontal stress (N 158° E) and with azimuth and dip of foliation.