The present invention relates to artificially reducing the porosity of any potential flow paths in the near-wellbore region of a well or in permeable zones within or surrounding a well. In doing so, the permeability in this the targeted region will be significantly reduced, thus, preventing unwanted flow of subsurface fluids. The present invention concerns a method comprising applying a first and second solution comprising scale precursors to the porous media, wherein following this application, at least a portion of the scale precursors form at least two insoluble salts. Additionally, the present invention concerns a kit of parts comprising the first and second solutions.

Methods and systems for the treatment of wells are disclosed. A method for treating a well comprises providing a treatment fluid comprising calcium-aluminate cement, water, and a cement set retarder; and introducing the treatment fluid into a wellbore. A system for treating a well comprises a treatment fluid comprising calcium-aluminate cement, water, and a cement set retarder; a vessel to contain the treatment fluid; a pumping system coupled to the vessel to pump the treatment fluid; and a conduit coupled to the pumping system.

Lipophilic fibers are effective media for cleaning non-aqueous fluids out of a subterranean wellbore. The fibers are preferably added to a drilling fluid, a spacer fluid, a chemical wash, a cement slurry or combinations thereof. Non-aqueous fluids, such as an oil-base mud or a water-in-oil emulsion mud, are attracted to the fibers as they circulate in the wellbore.

Pressure buildup can be extremely problematic during subterranean operations when there is no effective way to vent or otherwise access one or more sealed annuli within a wellbore. This condition can compromise casing integrity and ultimately lead to failure of a well. Methods for mitigating annular pressure buildup can comprise: providing a wellbore containing an annular space having one or more annuli therein; selecting a pressure-mitigating material based upon one or more conditions present within the annular space, the pressure-mitigating material having a negative coefficient of thermal expansion; introducing the pressure-mitigating material into the annular space of the wellbore; sealing at least a portion of the annular space after introducing the pressure-mitigating material thereto; and subjecting the pressure-mitigating material to a temperature increase in the sealed portion of the annular space to decrease a volume occupied therein by the pressure-mitigating material.

Wellbore synthesis techniques are disclosed suitable for use in geothermal applications. Embodiments are provided where open hole drilled wellbores are sealed while drilling to form an impervious layer at the wellbore/formation interface. The techniques may be chemical, thermal, mechanical, biological and are fully intended to irreversibly damage the formation in terms of the permeability thereof. With the permeability negated, the wellbore may be used to create a closed loop surface to surface geothermal well operable in the absence of well casing for maximizing thermal transfer to a circulating working fluid. Formulations for the working and drilling fluids are disclosed.

An object is to provide a dispersion of ultrafine cellulose fibers having a high thickening effect and a gelling function. There is provided a subterranean formation processing composition comprising ultrafine cellulose fibers, which has a haze value of 1.0% to 50%, when the composition is suspended in water such that the solid concentration of cellulose fibers is 0.2% by mass. The composition of the present invention can be used as an additive to the fluid at the time of the processing of subterranean formation, especially the processing of the well. The present invention provides also various fluids which are used in well processing. The present invention provides a method for processing a subterranean formation, for example, drilling of an exploratory well or a wildcat, an appraisal well, an exploratory well or an exploration well, a delineation well, a development well, a production well, an injection well, an observation well, and a service well; cementing; fracturing; and a method for producing petroleum resources.

Drilling fluid compositions include invert emulsion fluids having an oleaginous phase, an aqueous phase, and an emulsifier composition that includes an ethoxylated alcohol compound and a polyaminated fatty acid compound. The ethoxylated alcohol compound has the formula R.sup.1—(OCH.sub.2CH.sub.2).sub.n—OH, where R.sup.1 is a hydrocarbyl group having from 8 to 22 carbon atoms and n is from 1 to 8. The ethoxylated alcohol compound has a Hydrophilic-Lipophilic Balance (HLB) of less than or equal to 6. The polyaminated fatty acid compound has the formula R.sup.2—CO—NH—CH.sub.2—CH.sub.2—N(COR.sup.2)—CH.sub.2—CH.sub.2—NH—CO—R.sup.3, where R.sup.2 is a hydrocarbyl group having from 1 to 20 carbon atoms and R.sup.3 is a hydrocarbyl group having from 1 to 10 carbon atoms or an alkylene carboxylate group having formula —R.sup.4—COOH, where R.sup.4 is a saturated or unsaturated hydrocarbylene having from 1 to 10 carbon atoms. Methods of drilling wells include operating a drill in a wellbore in the presence of drilling fluid compositions.

An embodiment comprises a method of treating a subterranean formation comprising: providing a treatment fluid comprising a kiln dust, biowaste ash, and water; and introducing the treatment fluid into a subterranean formation. Another embodiment comprises a method of cementing comprising: introducing a cement composition into a subterranean formation, wherein the cement composition comprises a kiln dust, biowaste ash, and water; and allowing the cement composition to set in the subterranean formation. Yet another embodiment comprises a method comprising: providing a spacer fluid comprising biowaste ash and water; introducing the spacer fluid into a well bore to displace at least a portion of a first fluid from the well bore; and introducing a cement composition into the well bore, wherein the spacer fluid separates the cement composition and the first fluid.

A system for use in performing a reverse cementing operation in a downhole well operation and creating a sectional separation within a well casing and a process completion indicator. The system comprising a well casing, and a magnetic element, and a plurality of magnetizable particles. The magnetic element is coupled with a radial, interior section of the well casing and the plurality of magnetizable particles couple with the magnetic element forming an impediment between a first and second section of the well casing. The impediment creates a detectable resistive force. The magnetizable particles and the at least one magnet form a contiguous and porous wall and the resistive force creates a pressure spike at a surface of the well in response to the interaction of a cement slurry pumped into an annulus of a wellbore and the wall.

In one embodiment, a retarded acid system comprises an aqueous acid and a retarding surfactant. The aqueous acid may comprise from 5 wt. % to 25 wt. % of a strong acid, that is, an acid having a K.sub.a greater than or equal to 0.01. The aqueous acid may further comprise from 75 wt. % to 95 wt. % water. The retarding surfactant may have the general chemical formula R—(OC.sub.2H.sub.4).sub.X—OH where R is a hydrocarbon having from 11 to 15 carbon atoms and x is an integer from 6 to 10. The retarding surfactant may have a hydrophilic-lipophilic balance from 8 to 16.