Abstract: An insulation and corrosion protection system for a pipe includes a pair of elongated and cross sectionally semi-cylindrical segments of insulating material, and associated method of manufacture and installation. Each section of the insulating segments is made by wrapping a mandrel with an inner sleeve material, applying an elastomeric inner jacket, a layer of insulating material and outer jacket. A hinge is installed beneath the outer jacket for pivotally connecting the two semi-cylindrical portions of the structure. The insulating segment is completely encapsulated within an elastomeric jacket material to seal the insulating member. Before the insulating segment is installed around a pipe an elastomeric sealing material is applied to exposed edges of mating surfaces of the semi-cylindrical portions of the insulation segments. Then the semi-cylindrical portions are positioned around a pipe enclosing it.

Abstract: In the cathodic protection of tubular goods transporting fluids above 100.degree. F. with aluminum or zinc anodes, the output efficiency of the anode is increased by thermally insulating the anode from the tubular goods on which the anode is placed.

Abstract: Unconsolidated sand-like material in a subsurface formation adjacent a borehole of a water, oil, or gas well is consolidated by treating the formation first with a solution of alcohol and organic silicate and then with water. The water causes the organic silicate to hydrolyze and polymerize into a coating-like binding agent. The water also flushes excess organic silicate-alcohol solution from the more permeable portions of the formation adjacent the borehole, thereby maintaining the formation's permeability. The silicate solution may be preceded by alcohol without silicate. Organic silicate has many advantages over alkali metal silicate.

Abstract: An easy to manufacture, strong, high pressure flange-type insulating coupling with wide separation between exposed metal parts is provided. The insulating coupling is made up of two metal half flanges supported on a nonconductive cylindrical nonmetallic member. The space between the two vertical ends of the half flanges is wound in typical fashion with plastic impregnated glass fibers to provide the necessary working strength.

Abstract: In a water injection well, in place of corrosion inhibitors, the internal surface of a lower section of the casing is protected from corrosion by one or more galvanic sacrificial anodes placed in the section of casing. The anodes are mounted on a metal member which is connected to or suspended from the tubing or a well packer. The metal member extends below a certain point in the well into the section of casing. The metal member may be a tail pipe or it may be a wireline retrievable member specially prepared for this purpose. Anodes made of an aluminum alloy are especially suited to this corrosion protection system.