Abstract: Methods for adjusting the mechanical properties of cement systems include preparing a cement slurry containing water, an inorganic cement and at least two minerals. At least one of the minerals has a specific gravity higher than that of the cement at least one of the minerals has a specific gravity lower than that of the cement. The slurry is allowed to harden and form a set cement. The concentrations of the cement and the minerals may be varied such that the slurry has a constant solid volume fraction and a constant Compressive Strength vs. Effective porosity slurry density.

Abstract: A predetermined condition in a fluid-filled wellbore system can be detected by generating at least one sound in the wellbore system in response to the condition, such that a detectable change is created in some characteristic of the emitted sound, and detecting the at least one sound and the change, the detection being indicative that the predetermined condition has occurred. Equipment for facilitating detection of the condition can include a trigger operable in response to the condition; a generator operable to emit sound in the borehole and to create a detectable change in some characteristic of the emitted sound in response to the trigger; and at least one sensor operable to monitor the sound and detect the change, the detection being indicative that the predetermined condition has occurred. It is also possible to estimate a value of a property of a fluid-filled wellbore system.

Abstract: Cement plug parameters in a wellbore may be monitored by providing a cable through the cement plug before the cement plug sets. The cable comprises one or more sensors that monitor the parameters, and the sensors are operated to transmit measurement data to the surface. The parameters may include temperature, pressure, conductivity, vibration, acceleration and impedance.

Abstract: Compositions comprise polyacrylamide, a non-metallic crosslinker and a pH-adjustment material. Such compositions have utility in the context of remedial cementing, plug cementing in particular. The compositions may be pumped into a subterranean well, where they polymerize and form a support on which a cement plug may sit. The support may maintain the position of the cement plug in the wellbore and minimize cement-plug contamination.

Abstract: A predetermined condition in a fluid-filled wellbore system can be detected by generating at least one sound in the wellbore system in response to the condition, such that a detectable change is created in some characteristic of the emitted sound, and detecting the at least one sound and the change, the detection being indicative that the predetermined condition has occurred. Equipment for facilitating detection of the condition can include a trigger operable in response to the condition; a generator operable to emit sound in the borehole and to create a detectable change in some characteristic of the emitted sound in response to the trigger; and at least one sensor operable to monitor the sound and detect the change, the detection being indicative that the predetermined condition has occurred. It is also possible to estimate a value of a property of a fluid-filled wellbore system.

Abstract: A value of a property of a fluid-filled wellbore system can be detected. This can be accomplished by recording data including at least one of pressure and rate of flow at one or more locations in the wellbore system, and then estimating the value of the property by employing a model for predicting at least one of pressure and rate of flow dependent upon characteristics and locations of disturbances to pressure and flow in the wellbore system, in order to determine a best prediction of some attribute of the recorded data.

Abstract: A well treatment tool, comprising: a tool body; a clamping system for locating the tool body in a well; a positioning system for orienting the tool body in the well axially and azimuthally; a reservoir system comprising at least one fluid reservoir in the tool body; and a pumping system for pumping fluid from the reservoir to a region of the well to be treated. The treatment tool can also re-established the isolation performance of the casing, when modified (by drilling) for the treatment. The treatment tool is normally conveyed and controlled via the mean of an electrical wireline cable.

Abstract: Compositions comprise polyacrylamide, a non-metallic crosslinker and a pH-adjustment material. Such compositions have utility in the context of remedial cementing, plug cementing in particular. The compositions may be pumped into a subterranean well, where they polymerize and form a support on which a cement plug may sit. The support may maintain the position of the cement plug in the wellbore and minimize cement-plug contamination.

Abstract: Methods and related systems are described for controlling inflow of fluid into a production string. In aspects, the invention provides an inflow control device with a shut-off feature that is operated automatically utilizing swellable materials.

Abstract: A self-adaptive cement system includes cement, water and at least one additive that reacts or/and expands in contact with oil and gas. Several chemical products have been identified including rubber alkylstyrene, polynorbornene, resins such precrosslinked substituted vinyl acrylate copolymers and diatomaceous earth. These additives have the effect of making the cement self-healing in the event of physical failure or damage such as micro-annuli. The self healing property is produced by the contact with subterranean hydrocarbon fluids, the potential repair mechanism is thus activated if and when needed in case of start of loss of zonal isolation. In another embodiment, the expansion is deliberately induced by pumping a hydrocarbon fluid in the vicinity of the set cement.

Abstract: An apparatus for use in a wellbore, made of a casing and an annulus with a fluid within, comprises a reel or wound optic fiber line fixed to an object within the casing, and a light transmitter/receiver device that is able to generate a signal through the optic fiber line and to measure a change of said signal. The optic fiber line is (a) on a first position fixed to a reference point linked to the light transmitter/receiver device, and is (b) on a second position unwound from the reel. The light transmitter/receiver device is able to measure the change of said signal when occurring at the second position, and the apparatus has a system able to measure the flow rate of the fluid exiting the annulus at the surface.

Abstract: A field-responsive fluid which enters a semi-solid state in the presence of an energy field is improved by use of a plurality of energy field responsive particles which form chains in response to the energy field. The particles can be (a) composite particles in which at least one field-responsive member having a first density is attached to at least one member having a second density that is lower than the first density, (b) shaped particles in which at least one field-responsive member has one or more inclusions, and (c) combinations thereof. The particles improve the field-responsive fluid by reducing density without eliminating field-responsive properties which afford utility. Further, a multi-phase base fluid including a mixture of two or more substances, at least two of which are immiscible, may be used.

Abstract: A system for measuring a parameter within a well comprises a first and second apparatus. The first apparatus comprises a first reel of first wound optic fiber line (or fiber) able to be unwound from the first reel and at least a first sensor able to measure the parameter of the well, wherein information on the parameter can be transmitted through the first optic fiber. The second apparatus comprises a second reel of second wound optic fiber line able to be unwound from the second reel, an extremity of the second optic fiber being fixed to a reference point. A light transmitter or receiver device is linked to the reference point and able to generate or detect a light pulse through the second optic fiber line. Means to exchange the light pulse between first and second optic fiber line are also provided.

Abstract: A method for method of monitoring the parameters of a cement plug (2) in a wellbore comprises; pumping a cement slurry down a wellbore to form a cement plug (2); providing a cable (1) through the cement plug (2) before the cement plug sets, wherein the cable comprises a sensor (4) for monitoring parameters of the cement plug; locating the sensor at the bottom of the cement plug (2); operating the sensor to measure parameters of the cement plug; and transmitting information regarding the measurement to the surface.

Abstract: Method and apparatus for identifying lost circulation in subterranean wells, in particular, methods for treating the identified lost circulation zones with fluid compositions that are pumped into a wellbore enter voids in the subterranean-well formation through which wellbore fluids escape, and form a seal that limits further egress of wellbore fluid into the lost-circulation zone.

Abstract: A self-adaptive cement system includes cement, water and at least one additive that reacts or/and expands in contact with oil and gas. Several chemical products have been identified including rubber alkylstyrene, polynorbornene, resins such precrosslinked substituted vinyl acrylate copolymers and diatomaceous earth. These additives have the effect of making the cement self-healing in the event of physical failure or damage such as micro-annuli. The self healing property is produced by the contact with subterranean hydrocarbon fluids, the potential repair mechanism is thus activated if and when needed in case of start of loss of zonal isolation. In another embodiment, the expansion is deliberately induced by pumping a hydrocarbon fluid in the vicinity of the set cement.

Abstract: A method of constructing a borehole drilled with a drilling apparatus (16), the method comprises: connecting a flexible tubular liner sleeve (22) around the outside of the drilling apparatus and connecting the sleeve around an upper opening of the borehole so as to pass into the borehole; progressively extending the sleeve into the borehole as drilling progresses while maintaining connection to the drilling apparatus and borehole opening; at a predetermined point in the drilling, expanding the sleeve so as to contact the borehole wall; and setting the sleeve so as to be fixed to the borehole wall after expansion. Apparatus for use in such a method comprises: a flexible, expandable sleeve (22); a first connector for connecting the sleeve around the outside of a drilling assembly; and a second connector for connecting the sleeve around the opening of the borehole; wherein the sleeve is arranged to extend through the borehole between the connectors as drilling progresses.

Abstract: The invention provides apparatus for use in a wellbore (32) made of a casing (30) and an annular (33) with a fluid within, comprising: a reel (40) of wound optic fiber line (10) fixed to an object (20) within the casing, and a light transmitter/receiver device (12) able to generate a signal through the optic fiber line and to measure a change of said signal; wherein the optic fiber line is: (a) on a first position fixed to a reference point (4) linked to the light transmitter/receiver device, and is (b) on a second position unwound from the reel; wherein the light transmitter/receiver device is able to measure the change of said signal when occurring at the second position; and the apparatus having a system able to measure the flow rate of the fluid exiting the annular at the surface level Q.

Abstract: Tubewaves are used for detection and monitoring of feature state to enhance stimulation operations and remediate failure conditions. For example, proper sealing of perforations may be confirmed based on lack of a reflection of a tubewave by the perforations. Alternatively, at least one of amplitude, frequency, attenuation, dispersion and travel time associated with a tubewave and reflection may be used to determine feature state. If a sealant fails during treatment then the failure condition is indicated by appearance of a tubewave reflection. Consequently, the stimulation operation can be stopped in a timely manner, and remediation by means, for example, of pumping diversion fluid or dropping of balls, can be reinitiated until the difference between the expected responses and responses measured by the instrument along the segment to be stimulated confirm that sealing has taken place and that stimulation of the intended zone can resume.

Abstract: Methods and related systems are described for controlling inflow of fluid into a production string. In aspects, the invention provides an inflow control device with a shut-off feature that is operated automatically utilizing swellable materials.