Method of recovering hydrocarbons from carbonate and shale formations

Abstract

A method to mobilize for production bitumen, kerogen, heavy oil, other hydrocarbons, and hydrogen contained in a subterranean formation comprised largely of silicate and carbonate minerals that are capable of generating a series of chemical reactions, that once induced are self-sustaining. Such formations include bitumen carbonates, unconventional oil or gas shales and oil shales. The induced silicate-reactions, carbonate-reactions and resulting hydrocarbon-reactions and heat generated in the formation are sufficient to chemically and physically decompose much of the rock structure so that it becomes porous and permeable. These reactions also convert the solid bitumen, heavy oil, kerogen and other hydrocarbons to fluid or gaseous forms and create formation fluids and reservoir pressure to help move hydrocarbons to production wells. Waste heat generated by the method may be used to generate electricity, or for other uses.

Description

FIELD OF THE INVENTION[0001]The present invention relates to methods and systems to mobilize and produce hydrocarbons and related by-products from various sub-surface formations, including in particular, hydrocarbon-bearing impermeable carbonate and shale formations.BACKGROUND OF THE INVENTION[0002]New sources of conventional oil reserves have been significantly declining for several decades while the demand for energy has continued to grow. Conventional deposits of gas and oil in North America have essentially been found and largely depleted. The increasing demand in North America has been generally met by a combination of unconventional oil and gas production and oil sands production.[0003]The unconventional, oil sands and bitumen carbonate hydrocarbons are much more difficult and expensive to produce. Mineable oil sands production is well known and successful, but environmentally is a problem. Deeper oil sands are currently being produced with SAGD and / or solvent methods. Bitumen...

AI Technical Summary

Benefits of technology

This patent describes a method for producing oil and gas from a deposit of organic matter called "formation". The method involves injecting a fluid into the formation to induce reactions and fracturing the surrounding material to improve the flow of oil and gas through the formation. The main benefits of this method are that it reduces the cost of heating the formation during operations and increases the amount of oil and gas that can be recovered from the formation.

Problems solved by technology

The unconventional, oil sands and bitumen carbonate hydrocarbons are much more difficult and expensive to produce.

Mineable oil sands production is well known and successful, but environmentally is a problem.

Bitumen carbonates, located in the center of oil sands area of Alberta, are huge, solid and impermeable deposits, and have no known economic method of production.

Oil shales, such as the Green River formation comprise solid kerogens and likewise have no known economic method of extraction.

The recovery methods available to date have been unsuccessful in economically recovering hydrocarbons from the vast amounts of heavy hydrocarbons contained in solid impermeable carbonate rock formations such as the Grosmont carbonates and other bitumen carbonates of northern Alberta and the Green River formation oil shales and other unconventional oil shales.

These methods are generally relatively expensive and are environmentally poor.

Fire flooding or in situ combustion systems, such as toe to heel air injection (THAI), have also been attempted, but with limited success.

All of the three initial basic methods have several major economic and environmental drawbacks: a) large amounts of injected energy is required to power the process, which is expensive; b) large amounts of scarce water is used and polluted; and c) large quantities of greenhouse gases are generated and released to the atmosphere.

For unconventional oil or gas production extensive hydraulic fracturing is required, which is expensive and generally has similar or worse environmental problems.

The cost to continuously do this is the major reason these processes are so expensive.

If they work at all it appears they may be only marginally economic.

To attack and decompose more of the carbonate minerals to extend the improvement in permeability requires more very expensive on-going injections of heat and / or solvents Like the bitumen carbonates, the oil shales are definitely less receptive to the methods that have been considered successful in oil sands production.

They have also created a number of problems, such as immense fresh water usage and resulting contaminations.

Unconventional wells have very rapid decline rates and are very expensive.

Fracturing is a very expensive process that extracts a relatively small percentage of the hydrocarbons in place.

It also has been strongly criticized for its built-in greenhouse gas and other negative environmental impacts.

To date there is no reported means of economically extracting hydrocarbons from these kerogen deposits.

However, as is the case for the Talley process for carbonates, this process is essentially theoretical because heat must be injected continuously, thus making any in situ process prohibitively expensive.

There are currently no economic extraction solutions for the massive oil shale deposits, such as the Green River formation in Colorado, Utah, and Wyoming.

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