Abstract: The invention relates to an expandable liner for completing a hole in an underground formation, the liner being constituted by a spiral-wound strip with the longitudinal edges of the strip having complementary touching profiles so that after it has been expanded, the liner is circular in section. The invention also provides a method of completing a well finally or temporarily by installing a spiral-wound liner of the invention, expanding it, and optionally cementing it.

Abstract: According to the present invention, a composition and method for hydraulically fracturing a subterranean formation is provided. The composition comprises an aqueous mixture of a hydrated polysaccharide, preferably a galactomannan gum, the hydrated polysaccharide having a plurality of bonding sites; a crosslinking agent for crosslinking the hydrated polysaccharide at the bonding sites at the conditions of the subterranean formation with a polyvalent metal ion to form a polyvalent metal crosslink, thereby increasing the viscosity of the hydrated polysaccharide; and a controlled solubility compound for releasing a chelating agent for controllably breaking the polyvalent metal crosslink and bonding with the polyvalent metal ion released by breaking the crosslink, thereby decreasing the viscosity of the hydrated polysaccharide.

Abstract: A wellbore service fluid comprising viscoelastic surfactants in combination with means for controlling the concentration of at least partially charged sites within the fluid is described.

Abstract: A fluid that is useful in stimulation operations, and in particular, in hydraulic fracturing treatments, comprises a carrier fluid; a solvatable, crosslinkable polymer; a cross-linking agent that does not cause substantial cross-linking of the polymer at temperatures less than about 105° F. and a pH of about 10 or greater; and an organic amine stabilizing agent that has a first pKa or a pH in water of at least about 9.5. One group of such amines has the formula H2N—(R1NH)n—H where R1 is C1-C4 alkyl and n is from 1-6. In one embodiment, the cross-linking agent is an organic zirconate, such as bis(hydroxyethyl)glycine zirconate. The organic zirconate is effective to cross-link the polymer when the composition is at a temperature of at least about 105° F., and a pH of about 10 or higher, preferably a pH in the range of about 10.5-12.

Abstract: The present Invention relates to method to stimulate the production of hydrocarbons from a subterranean formation. In particular, the present Invention discloses and claims methods to enhance the removal of fracturing fluid from a fracture deliberately created in the formation, thereby increasing effective fracture length, and thereby increasing hydrocarbon production. The methods of the present Invention involve breaker schedules opposite conventional teaching—i.e., according to the Invention, the breakers are staged such that the fluid near the fracture tip breaks first creating a viscosity gradient which causes the fluid resident in the tip to move towards the wellbore where it is more easily removed.

Abstract: A wellbore service fluid comprising viscoelastic surfactants in combination with cross-linkable, preferably hydrophobically modified, water soluble polymers is described, particularly applicable to water control operations.

Abstract: The present invention concerns a fluid loss control agent for a petroleum industry (or analogous) cement slurry, comprising a surfactant and a micro-gel obtained by chemical cross-linking of a polyvinyl alcohol. The micro-gel and the surfactant are advantageously compatible with a wide range of petroleum industry cement additives and can also produce compositions which are gas tight.

Abstract: A fracturing fluid and method is disclosed comprising an aqueous metal hydrated galactomannan gum, buffered to a pH of from about 9 to about 11, and using reduced amounts galactomannan gum. Further, the invention provides a metal ion source, such as borate, to crosslink the galactomannan gum polymer in subterranean fractures. In one embodiment a slowly dissolving slurried borate is used in pumping an alkaline fracturing fluid into a subterranean formation to increase production of hydrocarbons. In another embodiment, an encapsulated borate source is used. A chemical stabilizer optionally may be used.

Abstract: A composition and uses of said composition are described for a latex based setting system for remedial and other operations within a wit bore. The composition comprises a pH-reducing agent and/or a coagulant. By controlling the amount of agent, the setting time of the system can be controlled in a range of 0.5 h to 15 h.

Abstract: A downhole cleaning tool (20) is suspended within a well tubular member (10) by coiled tubing (12) for the removal of deposits (29) within the tubular member (10). Tool (20) includes a hydraulic fluid motor (26) for rotating a combined fluid jetting and milling head (28). Fluid jetting and milling head (28) has a tapered body with a lower rounded nose (60). Embedded milling inserts or elements (62, 64) project outwardly from the tapered body and nose (60) to contact the deposit and are randomly spaced on head (28). A plurality of upper radial jets (70) extend above milling elements (62). Lower fluid jets or ports (78) extend from the lower rounded nose (60) of head (28). Power fluid from the coiled tubing (12) is divided at port (38) to the rotor bore (34) into a bypass fluid stream flowing through central bore (34) and a fluid power stream in annular passage (39) outside rotor (32) for rotation of rotor (32) and shaft (27) to rotate the fluid jetting and milling head (28).

Abstract: The addition of fibrous mixtures in intimate mixtures with particulates for fracturing and gravel packing decreases or eliminates the undesirable flowback of proppant or formation fines while stabilizing the sand pack and lowering the demand for high polymer loadings in the placement fluids. Fibers are useful for forming a porous pack in the subterranean formation. In some cases, channels or fingers of void spaces with reduced concentrations of proppant may be introduced into the proppant pack.

Abstract: The present invention provides a cementing composition for an oil or analogous well, essentially constituted by a solid fraction suspended in a liquid medium. The solid fraction is constituted by a coarse fraction with a packing volume fraction .PHI..sub.1 which, according to the invention, is maximised, and a fines fraction x with a packing volume fraction .PHI..sub.2 which is less than or equal to the volume fraction x.sub.0 such that ##EQU1## The invention also provides a method of maximising the value of .PHI..sub.1. The invention can minimise fluid loss whatever the materials selected for a cementing composition.

Abstract: A wellbore service fluid comprising polymers having cross-linking groups capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents is described, and related methods, particularly applicable to water control operations.

Abstract: The Invention relates to novel fluids and techniques to optimize/enhance the production of hydrocarbon from subterranean formations (e.g., "completion fluids"), in particular, fluids and techniques are disclosed and claimed which remove wellbore damage and near-wellbore damage in the form of coating formed from drilling and production-related operations ("filtercake"); the techniques can be applied either by themselves or in conjunction with other completion operations, such as gravel packing; preferred embodiments are chelating agent and enzyme systems in a viscoelastic surfactant (VES) matrix.

Abstract: A petroleum reservoir production modeling apparatus and method is disclosed which incorporates a complete (from reservoir to wellhead) production systems analysis system for the evaluation of petroleum reservoir production performance, using industry accepted techniques of analysis. A computer generated model facilitates the determination of well and formation properties in a computerized methodology, efficiently, reliably and accurately, thereby facilitating subsequent changes in wellbore properties to maximize well production. The method includes a rigorous analytic reservoir inflow performance model for a variety of well types and reservoir outer boundary conditions and drainage area shapes, and uses industry accepted production analysis techniques. These techniques accepted in the industry include material balance, decline curve analysis, and non-linear minimization procedures. Field-recorded production data is evaluated to obtain estimates of the well or formation properties.

Abstract: In one embodiment, the invention relates to a method or process, useful in cementing a well, especially a hydrocarbon well, which is characterized by the use of increased external and internal diameter liners, the method being characterized by provision and use of a novel liner and liner-tool assembly. Novel liner apparatus, a liner-tool assembly, and a fluid circulating tool are also disclosed.

Abstract: An improved method for cleanout of subterranean wells, such as hydrocarbon wells, is disclosed, the method being characterized by utilization of specified translocating fibers and/or platelets to aid in reduction of undesired fluids in the wellbore.