Abstract: The present invention provides a tool and method for obtaining at least one parameter of interest such as pressure of a subterranean formation in-situ. The tool comprises a carrier member for conveying the tool into a borehole, at least one selectively extendable member mounted on the carrier member for separating the annulus into a first portion and a second portion, a first port exposable to formation fluid in the first portion, a second port exposable to a fluid containing drilling fluid in the second portion, a first sensor for determining a first value indicative of a first portion characteristic, a second sensor for determining a second value indicative of a second portion characteristic referenced to the first value.

Abstract: A method of well logging in which the logging tool is delivered to the bottom of the well within a drill pipe and then the well is logged by withdrawing the drill pipe with the sensor portion of the logging tool protruding from the drill pipe. Following the logging operation, the logging tool is returned to the surface by reverse circulation.

Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like. The electrolytic salt or brine preferably includes a quaternary amine salt having the formula: wherein R is an alkyl having 8 to 18 carbon atoms, R′ is 2 to 6 carbon atoms alkyl group, B is hydrogen, oxyalkyl having 1 to 4 carbon atoms or alkyl having 1 to 4 carbon atoms, A is hydrogen or alkyl with 1 to 4 carbon atoms, x+y=1 to 15, z is 0 to 3, and M is a counter anion; or combinations thereof. The carbon dioxide buffer is preferably a trialkylanol amine.

Abstract: A hydraulic strain sensor for use with a downhole tool includes a housing having two chambers with a pressure differential between the two chambers. A mandrel is disposed in the housing. The mandrel is adapted to be coupled to the tool such that the weight of the tool is supported by the pressure differential between the two chambers. A pressure-responsive sensor in communication with the one of the chambers is provided to sense pressure changes in the chamber as the tool is accelerated or decelerated and to generate signals representative of the pressure changes.

Abstract: A method, of logging a borehole, for use in a cased oil well for detecting the gas/oil or water/oil contact in a hydrocarbon reservoir, using a neutron capture technique to detect one or more properties of fluid includes comparing the count rates from two or more radiation detectors spaced at respective first and second distances from an isotopic source of continuous neutron radiation. The contact detection criteria are arranged to be substantially independent of borehole fluid characteristics.

Abstract: An improved method to detect water influx using video monitoring of a cased wellbore is disclosed. A wireline well tool having a video camera and a light source is lowered into a selected borehole interval where water influx is suspected. The borehole fluid over the selected interval is displaced and replaced with either a water transparent mixture containing a viscosifying agent, a coloring agent and/or sufficient salt to increase mixture density; or a transparent water insoluble solvent. By use of either of these displacement fluids, the quality of video monitoring over the selected borehole interval for water influx, is enhanced.

Abstract: The present invention provides a method for improving the quality of a formation fluid sample by taking the sample at a time when the formation fluid composition contains the most favorable portion of hydrocarbons. This task is accomplished by determining in real-time, the composition of the fluid flowing into a downhole tool from the formation. This method determines the optical density of the fluid as the fluid flows through the tool. An optical density spectrum is generated from the optical density measurement. The optical density spectrum is compared to a composite optical density spectrum generated from a database of known fluid samples. As a result of the comparisons, there is a determination of the derivations between corresponding features of the two spectra. Adjustments are made to the components of the composite spectrum until the deviations between the two spectra are at an acceptable minimum.

Abstract: A method and apparatus for determining position in a pipe provides for the precise determination of location and associated characteristics of each pipe joint of a well, cross country pipeline or other fluid transmission line. The system includes a passive or active radio identification device at each joint in the pipe or casing string. The devices are preferably sealed within the resilient seal positioned between each pipe or casing joint. A pipeline tool includes a radio transmitter and receiver, with the transmitter transmitting on a frequency selected for resonating the identification devices. The resonant response of each device is detected by a receiver in the pipeline tool, with the response transmitted to the surface via the wireline to which the tool is connected. Alternatively, the tool may include storage information means until the tool can be recovered from the well or pipe.

Abstract: A method for actuating or installing downhole equipment in a wellbore employs non-acoustic signals (e.g., radio frequency signals) to locate, inventory, install, or actuate one downhole structure in relation to another downhole structure. The method comprises the steps of: (a) providing a first downhole structure that comprises a non-acoustic (e.g.

Abstract: Initially, signals relating to well bore fluids that are generated from sensors in presently available down-hole logging tools are analyzed and/or interpreted by an electronic circuit in a well logging tool. The interpretation of these signals can be direct, differential, or summation measurements from the sensors. The signal interpretations can be qualitative or quantitative, depending on how the tool is set up or programmed of the electronic circuit. When gas/oil, gas/water, or oil/water contacts are made in the well bore, the circuit will send a signal to a set of electromagnets or a drag mechanism that will momentarily grab the walls of the pipe. This will create a line tension spike on the load cell/weight indicator on the surface, and a well log can be generated to show where these line tension spikes occur, thus indicating the depth of various fluids in the well bore.

Abstract: A method of electrically logging subterranean wells using a conductive fluid in which the conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, and an electrolytic salt. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The medium may further include gelling agent, weight material, surfactant, or corrosion inhibitors. The polar organic solvent may preferably be a oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: A system is provided for drilling and logging of a wellbore formed in an earth formation. The system comprises a drill string provided with an external recess extending in longitudinal direction of the drill string, a fluid passage for flow of drilling fluid from an upper end of the drill string to a lower end thereof, and a port providing fluid communication between the fluid passage and the recess. The system further comprises a logging tool string capable of passing through the fluid passage and from the fluid passage via the port into the recess, and a removable closure element adapted to selectively close the port.

Abstract: A device for sensing and recording downhole data relating to an ambient environment in a production well and a method for obtaining such downhole data utilizing the device. Further, the device is used in combination with a downhole pump, and preferably, in combination with a strainer for the downhole pump. The device is connected with the downhole pump, and particularly the strainer, such that the device and the downhole pump may be conveyed or transported within, and retrieved from, the production well together or as an integral unit.

Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: The methods and apparatus of the invention include installing sensors in one or more of the many hole sections which are abandoned before the holes are sealed with cement. According to the invention, a sensor array is attached to the cement delivery device which is used to seal a hole which would otherwise be abandoned. The preferred apparatus for cement delivery is a “coiled tubing”. Preferably, the sensor array is passed through the center of the tubing so that it is protected from damage or snagging while being delivered to its deployment position. The coiled tubing may be withdrawn or left in place after the cement is delivered into the hole. When the cement cures, the sensor array is centered in the cement plug which seals the reservoir. According to the invention, the sensor array may be placed in any well which is to be abandoned.

Abstract: This disclosure describes a blended buoyancy oil well survey instrument capable of performing MWD measurements (measuring while drilling), where the well survey instrument is mounted. An oil well survey instrument in a closed cylindrical housing having a specific gravity greater than the drilling mud in which it is used is modified in buoyancy by attaching one of several identical elongate cylindrical hollow containers or cylinders to it. They are filled with light material. They are made sufficiently strong that they do not collapse at working pressures. The cylinders are provided with upper end and lower end threaded stub shafts and mating receptacles to thread together thereby providing a modified buoyant system. The method is concerned with adjustment of the buoyancy so that the rate of fall is modified; in conjunction with mud flow velocity in the drill string, the buoyant descent of the instrument is controlled to about 100 or 200 feet per minute.

Abstract: The present invention provides a method for improving the quality of a formation fluid sample by taking the sample at a time when the formation fluid composition contains the most favorable portion of hydrocarbons. This task is accomplished by determining in real-time, the composition of the fluid flowing into a downhole tool from the formation. This method determines the optical density of the fluid as the fluid flows through the tool. An optical spectrum is generated from the density measurement. The optical spectrum is compared to a composite spectrum generated from a database of known fluid samples. As a result of the comparisons, there is a determination of the derivations between corresponding features of the two spectra. Adjustments are made to the components of the composite spectrum until the deviations between the two spectra are at an acceptable minimum. Determinations of the fluid composition are made from the composition of the composite spectrum at the minimum deviation.

Abstract: A conveyance apparatus for conveying at least one logging tool through an earth formation traversed by a horizontal or highly deviated borehole. The conveyance apparatus comprises a pair of arcuate-shaped cams pivotally mounted to a support member, a spring member for biasing the arcuate surface of each cam into contact with the borehole wall, and actuators operatively connected to each cam. A logging tool is attached to the conveyance apparatus. When either actuator is activated in a first direction, the cam connected to the activated actuator is linearly displaced forward and the arcuate surface of the cam slides along the borehole wall. When either actuator is activated in a second direction, the activated actuator pulls the connected cam backwards and the spring member thereby urges the arcuate surface of the cam to lock against the borehole wall.