Abstract: A process is provided for using siliceous sludge (filter cake), obtained by precipitation of silica from silica-rich geothermal brine, to make a concrete material (geocrete). The process includes combining the sludge with a cementitious material, such as Portland cement and/or flyash and activating the cementitious material with an activating media. When water is used as the activating media, the sludge is preferably dewatered and the residual water content is determined, the entrapped brine adding to the water content of the mixture. The dry weight ratio of sludge to cementing material may be greater than about 3:1 and ratios as high as about 12:1 can be used to produce high strength geocrete.

Abstract: A process is provided for using silicious sludge (filter cake), obtained by precipitation of silica from silica-rich geothermal brine, to make a concrete material (geocrete). The process includes combining the sludge with a cementing material, such as portland cement and/or flyash and activating the cementing material with an activating media. When portland cement is used as the cementing material, the activating media is water. In such case, the sludge is preferably dewatered and the residual water content is determined, the entrapped brine adding to the water content of the mixture. Preferably, the dry weight ratio of sludge to cementing material is about 2:1 to about 3:1; although, ratios as high as 9:1 can be used when high strength of the geocrete is not required. The preferred amount of water used is about 40 weight percent, including water content of the sludge, which may typically be between about 10 and about 30 weight percent.

Abstract: A process for stabilizing silica-rich geothermal brine to prevent silica scaling comprises selectively providing a supply of ferric ions, allowing the silica-rich brine to combine with the ferric ions to form insoluble, iron-rich siliceous material and separating the insoluble siliceous material from the brine to form a brine having a silica content which is reduced below the saturation level required for substantially scale-free handling of the brine. In one embodiment of the process in which the brine contains sufficient dissolved ferrous ions, the process comprises selectively contacting the brine with an oxidizing agent, preferably by aerating the brine, to oxidize a selected portion of the ferrous ions to ferric ions, which then combine with silica to form the insoluble iron-rich siliceous material. The ferric ion content of an iron-deficient brine may be augmented by adding ferric and/or ferrous ions to the brine.

Abstract: An apparatus and method for handling a fluid stream containing gas, liquid and solid particulate matter, which fluid stream issues from a conduit at a high velocity, such as from a geothermal well during the drilling, producing, testing or treating of the well. The fluid is passed first through an expansion conduit comprising a series of axially-aligned sections of increasing cross-sectional area and then through a vertical separator for particulate matter and noxious materials. Means is provided for injecting a treating material into either the conduit leading from the well to the expansion-conduit, the expansion conduit or the vertical separator.

Abstract: Wellhead flow control apparatus for controlling the flow of fluids from a well producing fluids and debris including a novel device for separating and accumulating the debris. The device comprises an outer shell defining an enclosed accumulation chamber, a perforated outlet conduit communicating with the chamber to allow the passage of fluids but prevent passage of debris, and access means to facilitate periodic removal of the accumulated debris. The wellhead apparatus is especially useful for flow control of fluids from geothermal steam wells.