Project+Scope

Limitations of THAI:

 * 1. Geological factor **
 * Depending upon the distribution of the deposits underneath the surface, THAI cannot be used effectively if the deposits are too scattered, not sufficiently saturated or if they are located right under the earth’s surface[1].
 * THAI requires the injection of air under pressure to maintain proper combustion, which could lead combustion to the unwanted areas[2].


 * 2. Government regulations and other factors **
 *  Permit approval and Royalty payment[3] ( "usage-based payments made by one party (the "licensee") to another (the "licensor") for the right to ongoing use of an asset") would also limit or slow down the implementation of THAI technology. It is usually less cost effective to use the existing methods than introducing new ones.
 * Heavy residue from combustion, or coke material can drain into the horizontal well resulting in the formation of gas seals hence blocking the injected air’s passage through the well [4].

=**Down Hole Impact** =

 Since THAI is a fairly new method, its long term down hole impacts are yet to be fully understood. In general, the reclamation and damage to the land through in-situ combustion in THAI is much less relative to surface mining. Also many of these impacts pose mild short term risks; there can be long term effects on the soil and the environment. Some of such impacts are discussed below:
 * 1)  Although rare, the down hole upgrading process associated with THAI poses the risk of hydrocarbon leaching and spills down hole. The risk is even more elevated due to the areal span of the horizontal producers used . In addition to contaminating the soil and its entities, attempts at remediation of the spill requires specialized efforts.
 * 2) Greater efforts need to be focused in THAI towards controlling ground disturbance due to the shear quantity of down hole equipment requiring installation. Moreover, a nominally larger area of land (relative to other in-situ recovery techniques) is required for the operation of this technique demanding an elaborate regulatory assessment prior to the commissioning of any project.
 * 3) The contamination of the ground water or the aquifers is one of the biggest concerns when it comes to the environmental impacts of in-situ technologies. The important point is that the water used is unsuitable for any domestic or agricultural use. The waste water is normally disposed in deeper wells and not released to the environment. Although the short term effects on the ground water may seem minimum, they may become more significant in a long term, therefore effecting more underground waters as they may be connected in some cases. Leaching can also play an important role into taking this contamination deeper.
 * 4) Due to the high pressure air injection requirement of the THAI process, soil properties such as compaction, and texture might get compromised. Studies have shown that the soil chemical characteristics (i.e. total N, P, S, pH, and organic matter) might also unfavorably be affected in the long run because of emissions staying trapped underground and changes to the geomechanical and geochemical characteristics of the reservoir.
 * 5) The process setup demands for deforestation, disturbing wild life's natural habitat, which in turn results in the declination of biodiversity (down hole and surface).

=**Commercialization of THAI:** = 


 * <span style="background-color: transparent; color: #000000; font-family: 'Times New Roman',Times,serif; font-size: 120%; text-decoration: none; vertical-align: baseline;">To make the technology available on large scale it has to be licensed to other users. Newly licensed companies may also want to test this technology. Although construction of the well is a fairly quick process but still taking into consideration the cost and other factors like getting appropriate permits, planning new facilities and developing pipeline network, it will take several years to put substantial number of wells using THAI technology into operation.
 * <span style="background-color: transparent; color: #000000; font-family: 'Times New Roman',Times,serif; font-size: 120%; text-decoration: none; vertical-align: baseline;">Start up costs associated with engineering, construction, operation and maintenance and process education may outweigh the capital returns initially. This might lead to a delayed commercialization of THAI.
 * ======<span style="background-color: transparent; font-family: 'Times New Roman',Times,serif; font-size: 120%; vertical-align: baseline;">Social/technological determinism - concept where social interactions and constructs determine the <span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; line-height: 23px; vertical-align: baseline;">commercialization of a new technology. Current resources and infrastructure caters conventional in-situ recovery processes such as SAGD and CSS where as construction and execution of the THAI process would demand more resources and would also be time consuming. Moreover traditional technologies may be economically and environmentally stabilized. ======

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 * References: **

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;">[1] Cobb,K;Scitizen:Will Toe-to-heel air injection extend the oil age?[]

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;"> [2] Tverberg,G ;The Oil Drum:Canada, Extracting Heavy Oil:Using Toe to Heel Air Injection. []

[3] Wikipedia;http://en.wikipedia.org/wiki/Royalties

<span style="font-family: 'Times New Roman',Times,serif; font-size: 110%;"> [4] T. X. Xia, M. Greaves, University Of Bath, England; A. Turta, Alberta Research Council;Journal of Canadian Petroleum Technology,Volume 44,number 1.[]