Abstract: Methods and apparatus are provided which permit well testing operations to be performed downhole in a subterranean well. In various described methods, fluids flowed from a formation during a test may be disposed of downhole by injecting the fluids into the formation from which they were produced, or by injecting the fluids into another formation. In several of the embodiments of the invention, apparatus utilized in the methods permit convenient retrieval of samples of the formation fluids and provide enhanced data acquisition for monitoring of the test and for evaluation of the formation fluids.

Abstract: An acoustic system and method for monitoring a hydrocarbon reservoir. Wellbore tube wave energy may be created by natural or ambient sources or tube waves may be excited intentionally. Wellbore tube wave energy is converted to seismic body wave energy at minor borehole obstructions or irregularities. Each obstruction or discontinuity position along the borehole has an associated unique waveform source coda that may be measured for processing the body waves radiated into the earth formation surrounding the well bore. A plurality of sensors detects the radiated seismic energy after the seismic body wave energy has transited intervening earth formations. The system may be employed for permanent monitoring of mineral resources and resource management. Measurements of reservoir characteristics may be acquired at many different times over the productive life of a reservoir.

Abstract: A method is provided for gathering information on the pore pressure in an earth formation surrounding a wellbore. The method includes the initial steps of selecting at least one suitable property (e.g., porosity, drilling fluid composition, etc.) of the drilling environment (which is defined by the wellbore and the surrounding formation) and at least one NMR parameter (e.g., T2 distribution) in an NMR measurement response. The method selects a suitable property for which values over a plurality of wellbore depths can be correlated with the characteristics or behavior of the pore pressure in the earth formation. The method further includes conducting an NMR measurement at a plurality of wellbore depths, thereby generating an NMR response from the drilling environment. The measured values of the NMR parameter in the NMR response are then correlated with values of the suitable property.

Abstract: Methods and systems for estimating multi-phase fluid rates in a subterranean well (10). Stored and measured static (40) and transient (44) well conditions are used to model well conditions for comparison against additional transient data (42) relating to temperature, pressure, and flow. Multi-phase fluid rates are estimated by iteratively comparing well conditions with the model (30) for the well (10). Multi-phase fluid flow estimates may be obtained for the various liquid and gaseous fluids in the well (10) at multiple well locations (24).

Abstract: Subterranean reservoir monitoring method, computer system with programming code for implementing the method, and computer readable media and data signal embodying such programming code, the method including one or more of: (a) reservoir screening; (b) reservoir modeling; (c) generating model seismic data from a model; (d) model modification based on current VSP data; (e) repeating step (c) and step (d) until differences between the model and VSP data are as desired; (f) obtaining model production data from a reservoir model, and if necessary modifying the model and returning to step (c); (g) generating seismic model data for time t; and (h) comparing seismic model data with actual seismic data for time t, and if necessary modify the reservoir model and return to step (f) or modify the model of the subteranean and return to step (c).

Abstract: The invention relates to a borehole radar tool comprising, in a housing (2) a transmitting antenna and a receiving antenna both of which comprise, near the housing wall (2), a dipole antenna (8) and a reflector (10) opposite thereto. Also provided are an algorithm, method and apparatus for determining electromagnetic contrast information of a site into which electromagnetic fields (27) are emitted. Signals (29) generated by induction are intercepted and, using a back-projection algorithm including a suitable weighting factor, are converted into contrast information. The algorithm and/or method can be recorded in a computer program or on a data carrier. Also disclosed is a method of determining said weighting factor. The invention further provides a method and apparatus for subsurface surveys in which electromagnetic pulse signals are emitted.

Abstract: The present invention relates to a method whereby two well locations are employed to find a distribution of points where additional well locations can be found. The distribution of points form an arc defined as a trap slice. This distribution is determined in accordance with the equation An=Ae&thgr; cot &agr; wherein cot &agr; is a constant value determined on the basis of geometric data complied from existing well locations.

Abstract: Method for gradually deforming, totally or locally, a Gaussian or similar type stochastic model of a heterogeneous medium such as an underground zone, constrained by a series of parameters relative to the structure of the medium. The method comprises drawing a number p, at least equal to two, of independent realizations of at least part of the selected medium model from all the possible realizations, and linear combination of these p realizations with p coefficients such that the sum of their squares is equal to 1. This linear combination constitutes a new realization of the stochastic model and it gradually deforms when the p coefficients are gradually modified. More generally, the method can comprise several iterative gradual deformation stages, with combination at each stage of a composite realization obtained at the previous stage with q new independent realizations drawn from all the realizations.

Abstract: A method for determining the characteristics of a subterranean formation penetrated by an existing or drilled well is disclosed. The method uses a mathematical model to estimate formation parameters as fluid exits the formation through a hole and into the wellbore or tool. The model may be adapted to wells having a perforation extending from the wellbore into the formation by mathematically adjusting the perforation to the hole of the mathematical model. The formation properties may be estimated by mathematically eliminating the perforation and replacing it with an enlarged hole radius to simulate the mathematical model.

Abstract: The invention relates to a borehole radar tool comprising, in a housing (2) a transmitting antenna and a receiving antenna both of which comprise, near the housing wall (2), a dipole antenna (8) and a reflector (10) opposite thereto. Also provided are an algorithm, method and apparatus for determining electromagnetic contrast information of a site into which electromagnetic fields (27) are emitted. Signals (29) generated by induction are intercepted and, using a back-projection algorithm including a suitable weighting factor, are converted into contrast information. The algorithm and/or method can be recorded in a computer program or on a data carrier. Also disclosed is a method of determining said weighting factor. The invention further provides a method and apparatus for subsurface surveys in which electromagnetic pulse signals are emitted.

Abstract: Systems and methods for determining characteristics of geologic formations between conductively lined wellbores. At least one transmitter is axially disposed at a selected depth in a first wellbore and is attached to an external surface of a conductive liner. At least one receiver is axially disposed at a selected depth in a second wellbore and is attached to an external surface of a conductive liner. Both the transmitter and the receiver are attached to a surface control station. The transmitter generates a first magnetic field, and a formation magnetic field induced by the first magnetic field is detected by the receiver. The detected formation magnetic field is used to determine characteristics of the geologic formations.

Abstract: A well tester adapted to select among members of an oil well family to provide a purged and clean vessel to receive samples of well production that include gas and oil, and by selective use of production pressure and lease water under pressure, allow for the separation and separate measure of the oil and gas, and optionally to provide for improved sampling of production fluids with high gas/oil ratios.

Abstract: A method and probe for detecting the concentration of a substance in a measurement region in a subsurface exploration wherein the electromagnetic energy is delivered to this region and picked up from this region via an optical fiber and the measurement is taken or the electromagnetic energy is supplied at a number of locations within the region.

Abstract: The productivity of a formation is determined by stroking the drill bit up and down (swabbing) in the zone of interest for creating a suction in the wellbore and inducing the flow of hydrocarbons from the formation. The drilling mud 15 is first circulated to deplete hydrocarbon gas from the mud 15, the zone is swabbed, and the mud 15 is again circulated and the quantity of hydrocarbon gas contained therein is measured for comparison against that known for predetermined productivity. Preferably, the swabbing is performed enough times to ensure measurable production regardless of filter cake or invasion.

Abstract: The present invention provides a method for forming wellbores. In one method, one or more wellbores are drilled along preplanned paths based in part upon seismic surveys performed from the surface. An acoustic transmitter conveyed in such wellbores transmits acoustic signals at a one or more frequencies within a range of frequencies at a plurality of spaced locations. A plurality of substantially serially spaced receivers in the wellbores and/or at s receive signals reflected by the subsurface formations. The sensors may be permanently installed in the boreholes and could be fiber optic devices. The receiver signals are processed by conventional geophysical processing methods to obtain information about the subsurface formations. This information is utilized to update any prior seismographs to obtain higher resolution seismographs. The improved seismographs are then used to determine the profiles of the production wellbores to be drilled.

Abstract: A downhole tool and method are provided for collecting data from a subsurface formation during drilling operations. The tool includes a tubular mandrel adapted for axial connection in a drill string positioned in a wellbore penetrating the subsurface formation and a stabilizer element or sleeve positioned about the tubular mandrel for relative rotation between the stabilizer element and the tubular mandrel. A plurality of elongated ribs are connected to the stabilizer element. A means is connected to the stabilizer element for frictional engagement with a wall of the wellbore so as to prevent the stabilizer element from rotating relative to the wellbore wall. An actuator system is carried at least partially by the stabilizer element, and a probe is carried by one of the elongated ribs and adapted for movement by the actuator system between a retracted position within the one rib and an extended position engaging the wellbore wall such that the probe collects data from the formation.

Abstract: A downhole drilling efficiency sensor (DES) apparatus for use with drilling operations in oil and gas exploration, that accurately measures important drilling parameters at or near the drill bit in order to increase the effectiveness and productivity of the drilling operation. The parameters measured include weight-on-bit (WOB), torque-on-bit (TOB), bending-on-bit (BOB), annulus pressure, internal bore pressure, triaxial vibration (DDS—drilling dynamics sensor), annulus temperature, load cell temperature, and drill collar inside diameter temperature or thermal gradient across such drill collar. The direction of the bending-on-bit measurement is also determined with respect to the low side of the hole while rotating (or stationary) by using a triaxial vibration sensor and magnetometer array. Each of the parameters are known to be important factors in determining the direction, rotation, and rate of drilling.

Abstract: An apparatus and process for obtaining representative samples of fluids produced from one or more oil wells by means of a closed vessel chamber with lease water supply port connected to a lease water supply line, where a pressure sensor within such internal chamber is used together with a flowmeter and liquid-sensing probe or oil/water interface sensor employed in the fluid flow path lines to determine a rate of well production along with absolute or relative amounts of oil, water and gas contents.

Abstract: A method of relating three or four producing wells in an existing fossil fuel drilling field utilizes the equation Y2+X·Y−X2=0. The independent variable X represents the distance between any two known producing wells in the field. The dependant variable Y represents a distance between a known producing well and another well location, wherein each of the known producing wells and well locations depend upon which method utilized. In one method, a first origin well can be selected as a known producing well and then a distance from the origin well to a second producing well can be determined. Utilizing the above equation, a third well location can be determined by calculating a distance Y from the origin well to the third location. This well location can represent either an existing producing well located a distance from the origin well, or a new location at which a producing well can be drilled within the existing drilling field.