• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 458
  • 114
  • 113
  • 104
  • 13
  • 12
  • 8
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 4
  • Tagged with
  • 1035
  • 252
  • 140
  • 107
  • 96
  • 94
  • 79
  • 70
  • 67
  • 58
  • 57
  • 55
  • 54
  • 47
  • 45
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Modeling and Optimization of Matrix Acidizing in Horizontal Wells in Carbonate Reservoirs

Tran, Hau 03 October 2013 (has links)
In this study, the optimum conditions for wormhole propagation in horizontal well carbonate acidizing was investigated numerically using a horizontal well acidizing simulator. The factors that affect the optimum conditions are rock mineralogy, acid concentration, temperature and acid flux in the formation. The work concentrated on the investigation of the acid flux. Analytical equations for injection rate schedule for different wormhole models. In carbonate acidizing, the existence of the optimum injection rate for wormhole propagation has been confirmed by many researchers for highly reactive acid/rock systems in linear core-flood experiments. There is, however, no reliable technique to translate the laboratory results to the field applications. It has also been observed that for radial flow regime in field acidizing treatments, there is no single value of acid injection rate for the optimum wormhole propagation. In addition, the optimum conditions are more difficult to achieve in matrix acidizing long horizontal wells. Therefore, the most efficient acid stimulation is only achieved with continuously increasing acid injection rates to always maintain the wormhole generation at the tip of the wormhole at its optimum conditions. Examples of acid treatments with the increasing rate schedules were compared to those of the single optimum injection rate and the maximum allowable rate. The comparison study showed that the increasing rate treatments had the longest wormhole penetration and, therefore, the least negative skin factor for the same amount of acid injected into the formations. A parametric study was conducted for the parameters that have the most significant effects on the wormhole propagation conditions such as injected acid volume, horizontal well length, acid concentration, and reservoir heterogeneity. The results showed that the optimum injection rate per unit length increases with increasing injected acid volume. And it was constant for scenarios with different lateral lengths for a given system of rock/ acid and injected volume. The study also indicated that for higher acid concentration the optimum injection rate was lower. It does exist for heterogeneous permeability formations. Field treatment data for horizontal wells in Middle East carbonate reservoirs were also analyzed for the validation of the numerical acidizing simulator.
142

Late Precambrian and Cambrian carbonates of the Adelaidean in the Flinders Ranges, South Australia : a petrographic, electron microprobe and stable isotope study /

Singh, Updesh. January 1986 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Geology and Geophysics, 1987. / Includes bibliographical references (leaves 137-158).
143

Comprehensive model for modern lagoonal patch reef systems in Discovery Bay, Jamaica

Maher, Marie A. Bonem, Rena Mae. January 2007 (has links)
Thesis (M.S.)--Baylor University, 2007. / Includes bibliographical references (p. 90-92).
144

Localization of carbonic anhydrase in reproductive organs /

Ekstedt, Elisabeth, January 2005 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.
145

Carbon chemistry of giant impacts.

Abbott, Jennifer Ileana. January 1999 (has links)
Thesis (Ph. D.)--Open University. BLDSC no. DX227301.
146

Combined use of lcast-size measurements and wave-tank experiments to estimate Pleistocene tsunami size at Molokai, Hawaii /

Moore, Andrew Lathrop. January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Includes bibliographical references (p. [77]-86).
147

Calcium carbonate equilibrium in Lake Mendota

Hawley, John Edward, January 1968 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
148

Evaluating carbonate saturation effects on magnesium calcium core top calibration in benthic foraminifera

Jordan, Katherine A. January 2008 (has links)
Thesis (M.S.)--Rutgers University, 2008. / "Graduate Program in Oceanography." Includes bibliographical references (p. 35-39).
149

The effect of ammonium carbonate and aluminum chloride on the porosity of refractory material

Twyman, William Gail. January 1936 (has links) (PDF)
Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1936. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed June 9, 2010)
150

Phase distributions of the rare-earth elements in sediments

Collins, Kenneth Alan, January 1967 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Page generated in 0.0255 seconds