FIELD

The subject matter described herein relates to systems and methods for improving the production of oil wells.

BACKGROUND

Modern drilling systems often encounter heavy hydrocarbons in the subsurface. Due to the high viscosity, heavy hydrocarbons are typically either left behind in the reservoir (which reduces the volume of potential recovered hydrocarbons), or they accumulate to create what are known as “tar pads,” (or “tar mats”) that can clog the pores of a formation and trap the hydrocarbons within the well or borehole. This can create issues for reservoir management and drilling.

Current heating technologies such as steam injection are used to heat up the hydrocarbons (thereby lowering the viscosity) by injecting the steam from another well or by using cyclic steam stimulation. One drawback to this technology is that when steam cools in the formation, it becomes water which adds to the volumes of mixed fluid in the well, increases the required extraction energy, and necessitates downstream water/oil separation processes. In addition, the volume of water required for steam injection during production is enormous due to having to maintain the pore pressure high enough to enhance heavy hydrocarbon recovery.

SUMMARY OF THE INVENTION

The present disclosed embodiments include systems and methods that use laser generators to trigger a chemical reaction to break down heavy hydrocarbons in wells or boreholes. The systems and methods use arrays of laser generators and other heat sources at the borehole surface or within the borehole to heat the heavy hydrocarbons. The systems and methods may include hydrocarbon sensors within the borehole to detect gas seepage resulting from heating of the heavy hydrocarbons.

In one aspect, the present invention is directed to a borehole heating system including at least one laser generator disposed proximate at least one borehole, the generator producing at least one laser beam directed at a heavy hydrocarbon portion of the borehole. The laser beam heats up the heavy hydrocarbon portion, thereby changing at least one chemical property of the heavy hydrocarbon portion.

In some embodiments, changing at least one chemical property of the heavy hydrocarbon portion includes thermal decomposition, carbonization, pyrolysis and/or changing a viscosity of the heavy hydrocarbon portion.

In some embodiments, the system includes an array of laser generators.

In some embodiments, the laser generator is disposed at a borehole surface.

In some embodiments, the laser generator is disposed within the borehole.

In some embodiments, the system includes at least one laser generator disposed at a borehole surface, and at least one laser generator disposed within the borehole.

In some embodiments, at least one laser generator is oriented at a different angle with respect to a borehole centerline than at least one other laser generator.

In some embodiments, the system includes at least one infrared pyrometer for measuring at least one surface temperature of a formation.

In some embodiments, the system includes at least one infrared pyrometer disposed at a borehole surface.

In some embodiments, the laser generator may be vertically translated within the borehole, and the laser generator may be rotated within the borehole.

In some embodiments, the system includes at least one fluid analyzer disposed within the borehole.

In some embodiments, the fluid analyzer is disposed proximate to a first pore space, and a mixture of liquid and gas occupy the first pore space.

In some embodiments, the system includes at least one first mirror disposed within the borehole, mirror reflecting at least one laser beam from the laser generator at the heavy hydrocarbon portion.

In some embodiments, the system includes at least one first mirror disposed within the borehole; and at least one second mirror disposed at a borehole surface, the second mirror reflecting at least one laser beam from the laser generator at the first mirror. The first mirror reflects the reflected beam from the second mirror at the heavy hydrocarbon portion.

In some embodiments, the system includes at least one first laser generator disposed at a borehole surface, at least one second laser generator disposed within the borehole, the second laser generator mounted to a mounting arm, the mounting arm coupled to a hub, the hub coupled to at least one first leg, the first leg coupled to at least one second leg, the second leg coupled to at least one surface mount. The system further includes at least one infrared pyrometer for measuring at least one surface temperature of a formation; and at least one fluid analyzer disposed within the borehole.

In another aspect, the present invention is directed to a method of heating a borehole including: identifying at least one target location within the borehole; and directing at least one laser beam from at least one laser generator at the target location. Heavy hydrocarbons are disposed at the at least one target location.

In some embodiments, the method includes disposing at least one fluid analyzer within the borehole to identify the target location; and directing an infrared pyrometer at the target location to determine a temperature of the target location. Heat from the laser generator causes thermal decomposition of the heavy hydrocarbons.

In some embodiments, the method includes disposing at least one mirror within the borehole for reflecting at least one laser beam from the laser generator at the target location. The laser generator includes multiple laser generators, and the target location includes multiple target locations.

In some embodiments, the method includes disposing at least one fluid analyzer within the borehole to identify the target location; and determining that heavy hydrocarbons are present within the borehole based on information from the fluid analyzer. Information from the fluid analyzer includes a wetness ratio (Wh) of about 40 or higher and/or a character ratio (Ch) of about 0.5 or higher.

In another aspect, the present invention is directed to a borehole heating system including: an array of laser generators disposed at a borehole surface, the array of laser generators directing laser beams at a heavy hydrocarbon target location within the borehole. The laser beams heat the heavy hydrocarbon target location to a temperature range from about 100 degrees C. to about 600 degrees C.

In some embodiments, the system includes: at least one infrared pyrometer directed at the heavy hydrocarbon target location for measuring a temperature of the heavy hydrocarbon target location; at least one fluid analyzer disposed within the borehole; and at least one mirror for reflecting at least one laser beam of the array of laser generators. The mirror is disposed at a location at a surface of the borehole and/or within the borehole.

In some embodiments, each laser generator of the array of laser generators operates at a wavelength from about 100 nm to about 2 mm.

Throughout the description, where an apparatus, systems or compositions are described as having, including, or comprising specific components, or where methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are systems, apparatuses or compositions of the present invention that consist essentially of, or consist of, the recited components, and that there are methods according to the present invention that consist essentially of, or consist of, the recited processing steps.

It should be understood that the order of steps or order for performing certain action is immaterial as long as the invention remains operable. Moreover, two or more steps or actions may be conducted simultaneously.

The following description is for illustration and exemplification of the disclosure only, and is not intended to limit the invention to the specific embodiments described.

The mention herein of any publication, for example, in the Background section, is not an admission that the publication serves as prior art with respect to any of the present claims. The Background section is presented for purposes of clarity and is not meant as a description of prior art with respect to any claim.

