摘要:
In some embodiments, an apparatus and a system, as well as a method and an article, may operate to rotate a rotatable driving member having at least one driving lobe, and to periodically contact at least one cam on a unitary driven member with the at least one driving lobe during rotation of the rotatable driving member, to set the driven member in motion. This motion can be used to launch an acoustic wave along an axis substantially orthogonal to the axis of rotation of the driving member, where the driving member disposed completely within the driven member. The signature of the acoustic wave can be at least partially determined by the profile of the cam and the rotation rate of the driving member. Additional apparatus, systems, and methods are disclosed.
摘要:
A method for analyzing a subterranean formation porosity is disclosed. The apparent dielectric constant of the subterranean formation and an apparent resistivity of the subterranean formation are measured. The measured values are used to determine a measured formation loss tangent. The formation water loss tangent can be expressed by the water dielectric constant and the water resistivity. The measured formation loss tangent and the formation water loss tangent are then used to determine at least one of an actual dielectric constant of the subterranean formation water and an actual resistivity of the subterranean formation water. The actual formation porosity may be obtained using the estimated water resistivity and water dielectric constant.
摘要:
A method for analyzing a subterranean formation porosity is disclosed. The apparent dielectric constant of the subterranean formation and an apparent resistivity of the subterranean formation are measured. The measured values are used to determine a measured formation loss tangent. The formation water loss tangent can be expressed by the water dielectric constant and the water resistivity. The measured formation loss tangent and the formation water loss tangent are then used to determine at least one of an actual dielectric constant of the subterranean formation water and an actual resistivity of the subterranean formation water. The actual formation porosity may be obtained using the estimated water resistivity and water dielectric constant.
摘要:
Systems and methods for implementing and using a variable stiffness downhole tool housing including cylindrical segments positioned along a common axis, with a pair of segments each coupled to a bulkhead and positioned at either axial end of the tool housing are provided. The housing also includes a flexible cylindrical sleeve, positioned along the common axis between two of the plurality of cylindrical segments, that includes a first and second region with an outer diameter no larger than a common segment inner diameter and a third region located between the first and second regions and with an outer diameter no larger than a common segment outer diameter (the first and second regions each at least partially inserted into an end of one segment). A stiffness controller controls the stiffness of the tool housing by controlling at least part of an axial force exerted between the two segments.
摘要:
A method for analyzing a subterranean formation porosity is disclosed. The apparent dielectric constant of the subterranean formation and an apparent resistivity of the subterranean formation are measured. The measured values are used to determine a measured formation loss tangent. The formation water loss tangent can be expressed by the water dielectric constant and the water resistivity. The measured formation loss tangent and the formation water loss tangent are then used to determine at least one of an actual dielectric constant of the subterranean formation water and an actual resistivity of the subterranean formation water. The actual formation porosity may be obtained using the estimated water resistivity and water dielectric constant.
摘要:
An acoustic tool for evaluating a geologic formation includes a housing member disposed between transmitter and receiver sections of the acoustic tool. The housing member defines a change in direction in an acoustic path extending therethrough such that acoustic signals traveling through the housing member are delayed and disrupted. The delay and disruption may isolate the acoustic signals traveling through the housing member from acoustic signals traveling through the geologic formation. Thus, the acoustic tool may facilitate identification and evaluation of acoustic signals traveling through the geologic formation.
摘要:
A disclosed high-purity dipole transmitter has a longitudinal axis, an oscillation axis, and a side axis, each of the axes being mutually orthogonal. The transmitter includes an outer shell having external surfaces for displacing fluid along the oscillation axis. The transmitter also includes a reaction mass positioned inside the outer shell. The transmitter also includes an electromagnetic actuator that drives the outer shell relative to the reaction mass. The transmitter also includes a pair of matching springs separated along the longitudinal axis, where each spring is coupled between the outer shell and the reaction mass to enable compliant dipole motion of the outer shell along the oscillation axis while suppressing motion along other axes. Each spring includes a beam arrangement with each beam extending lengthwise in a direction parallel to the side axis and being thinnest in a direction parallel to the oscillation axis. The outer shell, the reaction mass, the electromagnetic actuator, and each spring, have mirror symmetry in a plane that includes the oscillation axis and the longitudinal axis, and have mirror symmetry in a plane that includes the side axis and the longitudinal axis.
摘要:
The disclosure addresses acoustic receivers including an acoustic isolator structure, and an acoustic logging tool which incorporates the acoustic receiver. The acoustic receiver isolation structure is configured to minimize acoustic transmissions which could otherwise adversely affect acoustical measurements being made by an acoustic receiver. The described acoustic receiver includes a plurality of longitudinally arranged mass members coupled to a central supporting structure, in a configuration to reduce acoustic transmissions in at least selected frequency ranges.
摘要:
A method for analyzing a subterranean formation porosity is disclosed. The apparent dielectric constant of the subterranean formation and an apparent resistivity of the subterranean formation are measured. The measured values are used to determine a measured formation loss tangent. The formation water loss tangent can be expressed by the water dielectric constant and the water resistivity. The measured formation loss tangent and the formation water loss tangent are then used to determine at least one of an actual dielectric constant of the subterranean formation water and an actual resistivity of the subterranean formation water. The actual formation porosity may be obtained using the estimated water resistivity and water dielectric constant.