Fracture permeability in the Matalibong-25 corehole, Tiwi geothermal field, Philippines

PDF Version Also Available for Download.

Description

The Tiwi geothermal field is located in southern Luzon on the northeast flank of Mt. Malinao, an andesitic volcano that was active 0.5 to 0.06 Ma. Matalibong-25 (Mat-25) was drilled through the Tiwi reservoir to investigate lithologic and fracture controls on reservoir permeability and to monitor reservoir pressure. Continuous core was collected from 2586.5 to 8000 feet (789 to 2439 meters) with greater than 95% recovery. The reservoir rocks observed in Mat-25 consist mainly of andesitic and basaltic lavas and volcaniclastic rocks above 6600 feet depth (2012 meters) and andesitic sediments below, with a transition from subaerial to subaqueous (marine) ... continued below

Physical Description

209-216

Creation Information

Nielson, Dennis L.; Clemente, Wilson C.; Moore, Joseph N. & Powell, Thomas S. January 24, 1996.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

The Tiwi geothermal field is located in southern Luzon on the northeast flank of Mt. Malinao, an andesitic volcano that was active 0.5 to 0.06 Ma. Matalibong-25 (Mat-25) was drilled through the Tiwi reservoir to investigate lithologic and fracture controls on reservoir permeability and to monitor reservoir pressure. Continuous core was collected from 2586.5 to 8000 feet (789 to 2439 meters) with greater than 95% recovery. The reservoir rocks observed in Mat-25 consist mainly of andesitic and basaltic lavas and volcaniclastic rocks above 6600 feet depth (2012 meters) and andesitic sediments below, with a transition from subaerial to subaqueous (marine) deposition at 5250 feet (1601 meters). The rocks in the reservoir interval are strongly altered and veined. Common secondary minerals include chlorite, illite, quartz, calcite, pyrite, epidote, anhydrite, adularia and wairakite. An <sup>39</sup>Ar/<sup>40</sup>Ar age obtained on adularia from a quartz-adularia-cemented breccia at a depth of 6066 feet (2012 meters) indicates that the hydrothermal system has been active for at least 320,000 years. Fractures observed in the core were classified as either veins (sealed) or open fractures, with the latter assumed to represent fluid entries in the geothermal system. Since the core was not oriented, only fracture frequency and dip angle with respect to the core axis could be determined. The veins and open fractures are predominantly steeply dipping and have a measured density of up to 0.79 per foot in the vertical well. Below 6500 feet (1982 meters) there is a decrease in fracture intensity and in fluid inclusion temperatures.

Physical Description

209-216

Subjects

Source

  • Proceedings, Twenty-First Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, CA, January 22-24, 1996

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: SGP-TR-151-30
  • Grant Number: AC07-95ID13274
  • Office of Scientific & Technical Information Report Number: 889774
  • Archival Resource Key: ark:/67531/metadc884723

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • January 24, 1996

Added to The UNT Digital Library

  • Sept. 21, 2016, 2:29 a.m.

Description Last Updated

  • Dec. 5, 2016, 4:30 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 2
Total Uses: 7

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Nielson, Dennis L.; Clemente, Wilson C.; Moore, Joseph N. & Powell, Thomas S. Fracture permeability in the Matalibong-25 corehole, Tiwi geothermal field, Philippines, article, January 24, 1996; United States. (digital.library.unt.edu/ark:/67531/metadc884723/: accessed June 21, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.