Abstract: A centralizer for centralizing a pipe is provided which collaborates the spring force of its bow springs. The centralizer includes a pair of end collars, and at least one center collar. Each of the collars has a center hole for coaxially receiving a pipe. In addition, the centralizer includes a plurality of longitudinally extending and arcuate bow springs having ends which affix to the end collars. The centralizer includes linkage arms which connect the center collar to the bow springs. The linkage arms may provide additional outward spring force against the bow springs. Preferably, the centralizer includes a mechanism for forcing the bow springs radially inward from their at rest position.

Abstract: New apparatus and methods are provided for positioning and attaching centralizers to the inside sidewalls of a wellbore. One or more centralizers are maintained in the interior of a pipe that is transported downhole into a well for deployment. Preferably, the pipe is also the wellbore's casing and the centralizers are deposited in a top-down manner as the casing travels downhole. The centralizers of the present invention are constructed to have an at least partially circular structure with a central hole. The preferred centralizer has an expanding circular structure wherein the diameter of the centralizer is substantially uniform so as to form an annular construction. Once deployed, the annular centralizer expands to engage the wellbore sidewall with the central hole expanded for passage of the well casing.

Abstract: A centralizer for centralizing a pipe is provided which collaborates the spring force of its bow springs. The centralizer includes a pair of end collars, and at least one center collar. Each of the collars has a center hole for coaxially receiving a pipe. In addition, the centralizer includes a plurality of longitudinally extending and arcuate bow springs having ends which affix to the end collars. The centralizer includes linkage arms which connect the center collar to the bow springs. The linkage arms may provide additional outward spring force against the bow springs. Preferably, the centralizer includes a mechanism for forcing the bow springs radially inward from their at rest position.

Abstract: New apparatus and methods are provided for positioning and attaching centralizers to the inside sidewalls of a wellbore. One or more centralizers are maintained in the interior of a pipe that is transported downhole into a well for deployment. Preferrably, the pipe is also the wellbore's casing and the centralizers are deposited in a top-down manner as the casing travels downhole. The centralizers of the present invention are constructed to have an at least partially circular structure with a central hole. The preferred centralizer has an expanding circular structure wherein the diameter of the centralizer is substantially uniform so as to form an annular construction. Once deployed, the annular centralizer expands to engage the wellbore sidewall with the central hole expanded for passage of the well casing.