Abstract: The present invention provides a well filter assembly for incorporation in a production system which will initially allow passage of particles which will only minimally damage the interior of the production system. After a period of time, the filter assembly will preclude passage of all damaging particles while allowing passage of those particles which will not deteriorate or obstruct the production system. Additionally, the well screen assembly is designed to mechanically break down the filter cake which was formed during drilling of the well in order to preclude plugging of the filter. Further, the filter of the prepacked well screen assembly is of sufficient strength so as to maintain its filtering capacity even after damage due to deformation. Finally, a method is provided for utilizing the well filter assembly in a production system.

Abstract: A prepacked well screen assembly for preventing sand from being produced with well fluids. The assembly includes a filter medium surrounded by an outer support, with the outer surface of the filter medium being fluted or otherwise shaped to have a larger outer surface area than the surface area of the outer support member surrounding the filter medium.

Abstract: A method of stabilizing a wellbore being drilled through both shale and sandstone zones. A shale stabilizing agent and finely divided particulate material are combined in a water based drilling fluid to provide the stabilization.

Abstract: Low permeability formations are hydraulically fractured with a fracturing fluid which includes a material capable of (1) bonding fine formation particles to prevent movement of the particles into and within the formation and (2) forming a permeability-reducing skin at the formation/fluid interface to reduce fluid leak-off into the formation. The stabilizing and fluid leak-off reducing material is comprised of a water soluble polymer and an alkaline potassium salt.

Abstract: A method of stabilizing perforations in a silty formation prior to gravel packing. The perforations are contacted with a polymer/salt composition as or shortly after they are formed.

Abstract: A method of forming a flow-restricting layer on a wellbore surface prior to cementing a casing string in the wellbore. The flow-restricting layer is formed by reaction of an injected fluid with divalent ions at and near the wellbore surface. The injected fluid is a composition containing a water-soluble polymer and one or more potassium salts.