Abstract: A natural gas production system prevents liquid accumulation in the wellbore and minimizes friction loading in the wellbore by maintaining production gas velocity above a critical minimum velocity. A pressurized gas is injected into the well to supplement the flow of production gas such that the velocity of the total gas flow up the well exceeds the critical velocity. A choke is fitted to the gas injection line, and total gas flows are measured by a flow meter. A flow controller compares the measured total gas flow rate against the critical flow rate, and determines a minimum gas injection rate required to maintain the total gas flow rate at or above the critical flow rate. The flow controller then adjusts the choke to achieve the desired gas injection rate. The injection gas may be recirculated production gas from the well, or a gas from a separate source.

Abstract: A new method for evaluating the efficiency of a sweep for removing cuttings from a borehole in a subterranean formation during a drilling operation. The method evaluates sweep efficiency on a “mass” in versus “mass out” basis. The method uses downhole density readings taken with a pressure-while-drilling tool inserted in the drill string. Measurements of hydrostatic pressure are converted into equivalent circulating density measurements which in turn are used in calculating the sweep efficiency. The method affords real time estimates at the wellsite of the quantity of formation cuttings brought out of a wellbore by a sweep.

Abstract: Roller cone drilling wherein the bit optimization process equalizes the downforce (axial force) for the cones (as nearly as possible, subject to other design constraints).

Abstract: Xanthan gels hydratable in brine, methods of making these xanthan gels, and methods of using these compositions in subterranean formation applications, such as gravel packing, are provided herein.

Abstract: A composition comprising expandable cross linked polymeric microparticles having an unexpanded volume average particle size diameter of from about 0.05 to about 10 microns and a cross linking agent content of from about 9,000 to about 200,000 ppm of labile cross linkers and from 0 to about 300 ppm of non-labile cross linkers. The composition is used for modifying the permeability of subterranean formations and increasing the mobilization and/or recovery rate of hydrocarbon fluids present in the formations.

Abstract: A method and apparatus for delivering a well treatment fluid to a productive zone of a subterranean formation at the same time that a well bore is being drilled is provided. The method includes the steps of delivering a drill-in fluid to a drill bit drilling a well bore in, or adjacent to, the productive zone; removing drill cuttings from the well bore; and simultaneous with these steps injecting the treatment fluid into the productive zone. The apparatus includes at least three nested tubes, which form one internal flow path and two annuluses. The drill-in fluid and drill cuttings are delivered to, and removed from, the drill bit, respectively, through the internal flow path and one of the two annuluses. The treatment fluid is delivered to the subterranean formation through the remaining annulus and an expandable bladder mounted to the intermediate and outer tubes.

Abstract: A simple debris removal apparatus for use in a wellbore. In one aspect of the invention a modular, interchangeable venturi is provided which can be retrofit into an existing debris bailer having a filter and a debris collection container. In another aspect of the invention, a venturi is utilized to create a negative pressure in a wellbore sufficient to actuate a retrieval tool for a downhole device. In yet another aspect of the invention, a combination tool is provided which can evacuate debris in a wellbore, thereby uncovering a downhole device which can then be removed in a single trip. In yet another aspect of the invention, a debris removal apparatus is provided with a method for utilizing the apparatus in a wellbore on coiled tubing.

Abstract: A method of retarding the set time of a cement composition comprising providing a cement composition that comprises water and a cement, and retarding the set time of the cement composition by including a copolymer retarder in the cement composition, wherein the copolymer retarder comprises olefinically unsaturated non-acrylate sulfonate monomers and olefinically unsaturated carboxylic acid monomers. Methods of cementing in a subterranean formation also are provided.

Abstract: Improved methods, apparatus, and systems for obtaining information regarding a formation, a casing, or fluid within the casing utilize an interrogator and one or more sensing devices attached to a casing in a wellbore. The interrogator, which is located and typically movable inside the wellbore, is effectively a toroidal transformer which includes an elongate conducting body surrounded by a core of high magnetic permeability material and carrying a winding. The sensing device, which is positioned and fixed in an opening cut in the casing, includes a housing, a sensor with associated electronic circuitry and an electrode. The electrode is insulated from the casing by an insulator, and the housing of the sensing device is typically adapted to provide a hydraulic seal with the opening in the casing. The interrogator and sensing device communicate in a wireless manner.

Abstract: Methods of treating subterranean zones and high density viscous aqueous treating fluids are provided. A high density viscous aqueous treating fluid of the invention comprises salt water comprising water and one or more oxidation resistant salts; a gelling agent; and a delayed oxidizing gel breaker.

Abstract: A method for drilling a wellbore in a formation using a drilling fluid, wherein the drilling fluid has a first temperature, and wherein the wellbore has a first wellbore depth. In one embodiment, the method comprises determining at least one fracture gradient, wherein the fracture gradient is determined at about the first wellbore depth; increasing the temperature of the drilling fluid from the first temperature to a desired temperature at about the first wellbore depth; drilling into the formation at increasing wellbore depths below the first wellbore depth, wherein at least one equivalent circulating density of the drilling fluid is determined at about the first wellbore depth; and setting a casing string at a depth at which the equivalent circulating density is about equal to or within a desired range of the fracture gradient. In other embodiments, an automated system is used to maintain the temperature of the drilling fluid at about first wellbore depth.

Abstract: A method and system for dissociating methane hydrate deposits in-situ is provided wherein an oxidizer fluid and a supply of fuel, both at a pressure higher than that of the methane hydrate deposit, are supplied and delivered to the methane hydrate deposit. The fuel is combusted downhole by reacting it with the oxidizer fluid to provide combustion products. The combustion products are placed in contact with a diluent fluid to produce a heated product fluid. The heated product fluid is injected into the methane hydrate deposit whereby methane is dissociated from the methane hydrate and made available for extraction. In addition, carbon dioxide may be made available to promote the formation of carbon dioxide hydrates from the liberated methane hydrate water.

Abstract: The apparatus is used for cutting an opening through the wall of a conduit located in a borehole traversing the subsurface formations. The apparatus includes a body adapted to be lowered into the conduit to a desired level. The body is formed by a cylindrical wall defining an elongated chamber having a combustible charge receiving portion and an ignition portion located close to the combustible charge receiving portion. A plurality of spaced apart apertures are formed through the wall defining a given pattern which may be at least one elongated row of apertures generally parallel with the axis of the cylindrical wall or a line which encloses a given configuration on one side of the axis.

Abstract: Methods and compositions for sealing subterranean zones having temperatures in the range of from about 80° F. to about 300° F. are provided. A method of the invention is basically comprised of the steps of providing a subterranean zone sealing composition that becomes substantially rigid when exposed to subterranean zone temperatures above about 80° F. and has a pH above about 8.5 comprised of water, a substantially fully hydrated depolymerized polymer and a cross-linking agent. The sealing composition is introduced into the subterranean zone whereby it becomes rigid and seals the zone. The sealing composition can subsequently be removed by contact with a fluid having a pH below about 8 when a boron compound is utilized as the cross-linking agent.

Abstract: Disclosed is a method to increase the bonding forces of a hydraulic cement to a subterranean pipe (such as a casing) by the addition of at least one cementitious expansive agent to increase the bulk volume of the cement plug and a latex. The method includes positioning a platform in a downhole pipe below the desired cement plug interval, positioning a plug dump bailer tool comprising a chamber for cement slurry and a valve to discharge the cement slurry on and above the platform, and discharging the cement slurry. The cement slurry includes an expansive agent and latex to increase the shear-bond between the downhole pipe and the cement plug.

Abstract: Methods of fracturing a subterranean formation include providing a fracturing fluid having a first pH. The fracturing fluid may be made by combining a gelling agent, a surfactant, and a proppant. The surfactant is capable of facilitating foaming of the fracturing fluid at the first pH and defoaming of the fracturing fluid when its pH is changed to a second pH. The methods of fracturing the subterranean formation further include foaming the fracturing fluid having the first pH and subsequently pumping it to the subterranean formation to fracture the formation. The pH of the fracturing fluid changes to a second pH, for example via in situ contact with an acidic material, causing the level of foam in the fracturing fluid to be reduced. As a result of the reduction of the foam, the fracturing fluid deposits the proppant into the fractures formed in the subterranean formation.

Abstract: A method for controlling drilling mud density at a location either at the seabed (or just above the seabed) or alternatively below the seabed of wells in deep water and ultra deep water applications. The mud recirculation system may be used in conventional drill bit drilling operations or with drilling with casing operations. Drilling mud is combined with a non-gaseous base fluid of lesser density than the mud required at the wellhead to produce a diluted mud in the riser. By combining the appropriate quantities of drilling mud with base fluid, a riser mud density at or near the density of seawater may be achieved. The base fluid may be injected utilizing a wellhead injection device for attachment to the wellhead and for injecting the base fluid into the rising drilling mud at a location below the seabed. The riser charging lines are used to carry the low-density base fluid to the injection device for injection into the drilling mud below the seabed.

Abstract: A tong positioning system positions a power tong about an oilfield tubular connection to make up or break out a threaded connection. An extendable arm and a retainer device on the extendable arm. In a preferred embodiment, the retainer device comprises opposing laterally-movable retainer arms defining an adjustable opening for at least partially enclosing one of the upper tubular and the lower tubular. The extendable arm is retractable for thereafter moving the power tong laterally toward the tubular connection.

Abstract: Cement compositions with improved mechanical properties and associated methods are provided, which are useful in conjunction with subterranean well operations. In certain embodiments, the cement compositions comprise carbon fibers, rubber particles, a hydraulic cement material, sufficient water to form a pumpable slurry, and optionally other ingredients including a dispersant, a weighting agent, a retarding or accelerating agent, or the like.

Abstract: Equipment and methods which may be used in conjunction with an underbalanced well completion. In a described embodiment, a valve for use in a subterranean well in conjunction with a tool conveyed through the valve in a container is provided. The valve includes a passage formed longitudinally through the valve, a closure assembly which selectively permits and prevents flow through the passage, and an engagement device which engages the container as the tool is conveyed through the passage. The closure assembly permits flow through the passage when the container is conveyed into the passage, and the closure assembly prevents flow through the passage when the container is removed from the passage. Engagement between the container and the engagement device separates the tool from the container.