Erosion resistant, self and/or artificial external cleaning solid exclusion system

#This invention relates to solids exclusion. More particularly, this invention relates to a solids exclusion system that includes a filter characterized by porosity and permeability designed to optimize production at multiple specified intervals, and made of materials resistant to erosion by any solids and/or resistant against corrosion by any chemicals commonly used in drilling, or produced from, and/or injected into a well. In addition, the present invention makes it possible to circulate flow at the outside of the filter to remove any solids and/or fluids which can accumulate and prohibit flow; and, further, it can be employed to inject or produce any fluid and/or solids outside the filter. The invention can be used in any bore hole, lined or open hole, into any earth formation whether it is used for injection, production, and/or circulation of fluids, solids or any combination thereof.

#In the production of hydrocarbons from earth formations, wellbores are drilled into reservoirs or pay zones. Such wellbores are completed and perforated at one or more zones to recover hydrocarbons from reservoirs. Many oil and gas wells produce fluid from underground formations containing solid particles, which are loose and/or not strongly attached to each other and when hydrocarbon-containing fluid is produced, it tends to carry entrained solids with it. These solids can cause serious damage to well equipment due to erosion. Erosion is particularly bad when a disproportionate amount of flow is concentrated in a relatively small region, resulting in high velocities of the solids. These regions are called “hot spots”.

#Filters, normally called sand screens of various designs, and slotted liners are commonly placed opposite the formation and below the production tubing in the well bore preventing entry of solid particulates into the tubing. Filters of different makes and configurations are commonly used as solids control devices. Filters currently available in the art typically erode substantially over time. In addition, they cannot effectively produce all zones because of the fact that the pressure differential required varies over the zones, which creates “hot spots” as mentioned above. Furthermore, there is currently no method available of filter cleaning by circulation of fluids, with or without additives, outside the filter.

#FIG. 1 is a longitudinal, cross-section view of one embodiment of the present invention.

#FIG. 2 is an enlarged view of one section of FIG. 1 showing a seal.

#FIG. 3 is a longitudinal, cross-section view of one embodiment showing a sub-section of the screen with connections, pin and box at each end.

#The solids exclusion system of the present invention can be deployed in a well bore in an earth formation that is lined or unlined with steel or any other material.

#The first embodiment and key part of the solids exclusion system is a filter made of erosion resistant material having selected porosity, permeability and other flow characteristics for one or more specific intervals. The filter is manufactured in such a manner that the porosity and permeability can have selected values in both radial as well as longitudinal direction. This will enable the free passage of solids through the body of the filter, after they have passed the wall of the filter.

#There can be at least two versions of the solids exclusion system, one for allowing flow from outside in, having a lower porosity outside than inside, and one from inside out having a lower porosity inside than outside. Also porosity and permeability differences in the vertical direction can be achieved by the manufacturing process, thus allowing programmable flow resistance in longitudinal direction along the filter axis.