In situ exploitation of deep set porphyry ores
US4291920A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1980 |
| Grant date | Sep 29, 1981 |
| Priority date | — |
| Expiry date | Apr 30, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/28
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Disclosed is a method of economically exploiting deep set porphyry ore bodies of the type containing metal values such as sulfidic copper nickel or uranium minerals and minerals capable of absorbing copper, uranium and nickel ions. The method involves establishing communication with the ore body through access and recovery wells and passing fluids sequentially therethrough. If necessary, thief zones of as low as 25 to 50 md in igneous rock of 1 to 5 md are prevented from distorting flow, by the injection of a polymeric solution of macromolecules with molecular weights of the order of 5 million along the entire wellbore, the higher permeability zones initially accepting the majority of the flow and being impaired at a much faster rate than the less permeable zones. In a first stage, the permeability of the leaching interval is stimulated as an ammoniated solution of sodium, potassium, or ammonium nitrate or chloride contacts calcium containing minerals to promote ion exchange, resulting in clay contraction or calcium carbonate dissolution. In a second stage, the leaching interval is primed as calcium ion is displaced with an aqueous solution of ammonium salt, a calcium sulfate scale…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.