Optical dietary fiber measurement from stress and you may temperatures

  • 6 August 2022
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Optical dietary fiber measurement from stress and you may temperatures

Tank climate is governed generally of the reservoir’s distance to the planet’s mantle, by this new cousin temperatures exchange capacities and you may thermal conductivities off new formations developing the latest lithostatic succession detailed with this new reservoir.

New geothermal gradient through the warmth-replace procedure varies from basin so you can basin, but within this a specific town the newest variations is actually short. For the majority hydrocarbon-producing section, the latest gradient is oftentimes in the directory of 0.6 to one.6°F for each one hundred ft out-of depth boost (Fig. 3). Places that the brand new world’s crust is thinner than simply mediocre, such as for instance volcanic and you can geothermal components, possess much higher gradients. During the slim-crust portion the new gradient alter averages cuatro°F for each and every one hundred foot regarding depth raise. Regional temperature gradients from the breadth were claimed of up to 10°F each one hundred base dealing with singularities (e.grams., major defects, aspects of tectonic path) in the planet’s crust within the geothermal components.

To decide an exact geothermal gradient, the fresh chose really should be shut-in, as opposed to disturbance, having a period enough to help conduction outcomes equilibrate the newest temperature. The warmth questionnaire should be presented regarding facial skin so you’re able to base for the the initial origin into the better and also at a slow rates (essentially, no more than 31 base/minute to match the fresh thermal inertia of one’s detector). This technique is necessary given that passage through of the thermometer alters the brand new static gradient. Defects introduce within the very first lineage-if seen or otherwise not-get disappear into the then studies immediately following disruption of one’s initially thermal equilibrium.

The virgin reservoir temperature may be determined when drilling initial exploration and appraisal wells by using the maximum temperatures recorded on successive logging runs or wireline sampling operations. The technique [1] calls for plotting Tbh vs. (tk + ?tc)/?tc on a linear scale.

These data are interpreted in Horner analysis fashion by drawing a straight line through the data points and extrapolating to the reservoir temperature at (tk + ?tc)/?tc = 1, which corresponds to infinite shut-in time. Even though this approach is not mathematically rigorous, it provides reliable estimates of the static temperature when short circulation times are assumed. This technique is especially applicable to regions with high geothermal gradients, where the temperatures recorded at the time of logging runs can be significantly lower than the static temperature.

Dimensions out-of tank tension and you can heat

Of a lot procedure can be found to possess getting bottomhole tank stress and you can temperature. A variety of logging techniques can be used. Select Getting bottomhole pressure and you will heat investigation to learn more. The strategy demonstrated here are growing process or special considerations.

Several options are now being made to promote stress and temperature dimensions distributed across the length of a keen optical fiber that’s forever deployed on completion. An advantage of fiber optic technologies are the detectors keeps no electronic elements within depth, so that they are far more legitimate. In addition, optical devices was:

  • Resistant in order to amaze
  • Maybe not likely to electromagnetic interference
  • Operable in the higher temperatures

Even when an exact gradient isn’t needed, pursuing the process continues to be recommended for powering temperature surveys for the wells (shut-from inside the, inserting, or streaming)

Dietary fiber optic technology is according to exposing the latest dietary fiber to help you periodic ultraviolet (UV) white activities that creates a good “grating” inside it. Pressure and you can heat distinctions change the reflection wavelength of gratings and will be decoded according to the repaired, incipient working wavelength. The machine try care about-referencing.

All the section marketed over the length of the new fiber provides the potential to build an alternate temperatures dimension. The benefits is actually dimension away from a permanent temperature gradient along the length of new soluble fiber while the capability to get a hold of certain measurement affairs. Single-area and you will marketed temperature devices was basically claimed to operate successfully from inside the steamflood wells up to 575°F. In one stated instance, heat dimensions pulled with each other a horizontal wellbore within differing times displayed steamchests, liquids discovery, crossflow, and you will disperse trailing tube.