Property:FieldProcedures

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Property Name FieldProcedures
Property Type Text
Description Description of actions, equipment and footprint of the exploration activity


Pages using the property "FieldProcedures"

Showing 24 pages using this property.

A

Acoustic Logs +The geophysical/well logging service company conducts the down hole logging operation and produces both digital and hard copy logs. The Drilling contractor trips the drill pipe and bit and conditions the well bore for logging.

C

Caliper Log +The geophysical/well logging service company conducts the down hole logging operation and produces both digital and hard copy logs. The Drilling contractor trips the drill pipe and bit and conditions the well bore for logging.
Cement Bond Log +The geophysical/well logging service company conducts the down hole logging operation and produces both digital and hard copy logs. The Drilling contractor trips the drill pipe and bit and conditions the well bore for logging.

D

Density Log +The geophysical/well logging service company conducts the down hole logging operation and produces both digital and hard copy logs. The Drilling contractor trips the drill pipe and bit and conditions the well bore for logging.

G

Gamma Log +Typically run as one logging method in a standard suite of bore-hole logs.
Ground Electromagnetic Techniques +[[Electromagnetic Profiling Techniques]]<br><br> [[Electromagnetic Sounding Techniques]]

H

Hand-held X-Ray Fluorescence (XRF) +Analysis is performed by placing the analyzer in contact with the sample and pulling a trigger to activate the x-ray/gamma-ray beam. Analysis of major and trace elements typically takes only a few seconds, allowing for numerous analyses to be performed over the course of a single field session. Data can be displayed on a built-in screen or a personal field computer for most devices, and can be exported for further interpretation.

I

Isotopic Analysis- Fluid +Liquid and/or gas samples are collected in the field at the surface or from wellbores. The [[Water Sampling]] and [[Gas Sampling]] technique pages should be consulted for specific details regarding standard sampling procedures of fluids in the field.
Isotopic Analysis- Rock +Rock samples are collected in the field at the surface or as core cuttings from depth. The [[Rock Sampling]] technique page should be consulted for specific details regarding standard rock sampling procedures.

M

Macrophotography +Macro photography can be performed during field mapping and requires very little equipment. A simple digital camera with a macro lens is used. A tripod is recommended for high quality photos, but it is not required. There are many different macro lenses on the market that suffice for taking macro photography for geothermal purposes. In order to get a larger than life size photo of the subject of interest the photographer must be able to get the camera very close to the subject. [[File: IMG_6600.JPG|thumb|center|500px| Macro photograph of alteration minerals from the Seltun Geothermal Area in Krysuvik Iceland. Photograph by Darren Atkins]] [[File: IMG_6682.JPG|thumb|center|500px| Macro photograph of alteration minerals from the Seltun Geothermal Area in Krysuvik Iceland. Photograph by Darren Atkins]]
Magnetic Techniques +See [[Ground Magnetics]]; [[Aeromagnetic Survey]]
Magnetotelluric Techniques +See [[Magnetotellurics]]; [[Audio-Magnetotellurics]]; [[Controlled Source Audio MT]]; [[Z-Axis Tipper Electromagnetics]]
Microgravity-Hybrid Microgravity +Microgravity measurements require that the precise location of the gravity measurement be reoccupied for consistency within the dataset. For additional information on the gravity survey, refer to [[Ground Gravity Survey]].

P

Pressure Temperature Log +After a well has been drilled and fluids have stopped circulating the temperature of the well is expected to equilibrate with the surrounding rocks in a matter of hours to days. Once equilibration is reached a temperature-pressure tool is lowered into the hole to take measurements as it descends into the hole. This is done at the well head.

R

Reflection Survey +See [[Active Seismic Techniques]]
Refraction Survey +See [[Active Seismic Techniques]], [[Passive Seismic Techniques]]<br><br>The field procedures for a seismic refraction survey are similar to a seismic reflection survey; the main difference is that a refraction survey requires a greater source-receiver distance to measure the refracted wave.
Rock Sampling +'''Subsurface Sampling''' A rock sample for geothermal exploration is typically collected from a drilled well, and initial analysis of the rock type, mineralization, composition, textures, etc. are collected in the field at the drill site or from core and cutting samples that have since been stored in a repository. However, the more in depth rock properties often require laboratory tools. '''Surface Sampling'''<br/> There are rock samples that can be collected on the surface, in outcrop, which may reveal important information about the geothermal resource at depth. These hand samples can be collected using a rock hammer or sledge.

S

Self Potential +A Self-Potential survey is a passive, non-invasive geophysical technique. The field equipment required for an SP survey is very minimal. Two non-polarizing electrodes, an insulated cable, and a high impedance voltmeter are required. The electrodes are generally buried at a depth of less than 0.5 meters. The means of access to the station (truck, hiking, etc.) is the largest impact associated with an SP survey.
Slim Holes +Slim holes require less of a footprint for drilling, smaller rig, less water, and can mobilize much quicker than traditional wide rotary holes (Hinchliffe).
Step-out Well +A step-out well is drilled some distance from the known reservoir for exploration purposes but drilling procedures are similar to that of [[Development Drilling]]. Also see [[Production Wells]]

T

Time-Domain Electromagnetics +The equipment involved in a TDEM survey is: a transmitter unit; a receiver unit; transmitting insulated wire; a receiver coil or antenna; and 2 12V batteries (depending on the TDEM instrument). TDEM systems are transportable by backpack with 2-3 people (depending on the wire length and gauge, transmitter type, battery weight, etc.). <br><br>The insulated wire is placed on the ground in a loop configuration. The area of the loop depends on the desired depth of investigation for the survey. An electrical current is applied to the transmitter loop, then the current is shut off and the decay response of the secondary magnetic field (see Data Access and Acquisition, below) is measured at the receiver coil. The measurement itself takes a few minutes to acquire, and then the wire can be picked up to move to the next station. TDEM does not require direct contact with the soil for data acquisition.

V

Vertical Seismic Profiling +There are numerous methods for acquiring a vertical seismic profile (VSP). *'''Zero-offset VSPs''' have sources close to the wellbore directly above receivers. *'''Offset VSPs''' have sources some distance from the receivers in the wellbore. *'''Walkaway VSPs''' feature a source that is moved to progressively farther offset and receivers held in a fixed location. *'''Walk-above VSPs''' accommodate the recording geometry of a deviated well, having each receiver in a different lateral position and the source directly above the receiver. *'''Salt-proximity VSPs''' are reflection surveys to help define a salt-sediment interface near a wellbore by using a source on top of a salt dome away from the drilling rig. *'''Drill-noise VSPs''', also known as seismic-while-drilling (SWD) VSPs, use the noise of the drill bit as the source and receivers laid out along the ground. *'''Multi-offset VSPs''' involve a source some distance from numerous receivers in the wellbore. 3D and 4D VSP surveys have become more common since 1998 when the first long down hole seismic array became available. 3D and 4D VSP surveys have become more common since 1998 when the first long down hole seismic array became available.

W

Well Deepening +After a drilling target is determined if there is an existing well at or near the target location well deepening might be considered. Not all wells can be deepened depending on their diameter and how they were drilled and cased. If a well can be deepened it should be cleaned and then drilling procedures would be similar to drilling any other well except the beginning of the well is already completed. See [[Production Wells]] [[File: Calpine well drilling.jpg |thumb|center|400px|Geothermal production well at Imperial Valley, California. The drilling of production wells, such as this one in southern California, results in one-third to one-half of the cost of a geothermal project. The DOE Geothermal Energy Program pursues the development of technologies that will considerably reduce the cost of drilling these wells.]]

X

X-Ray Diffraction (XRD) +Sample collection in the field is relatively simple, and only requires a minimal amount (tenths of a gram) of the material of interest to be collected. The sample should be as pure as possible, and extra material should be collected if repeat analysis is desired.