Patent EA-005125-B1 (EA)
Title: Reservoir monitoring
Inventor: TAYEBI DAVOUD
IPC: E21B47/10
Filed: 2001-02-19
Abstract: 1. A method of monitoring hydrocarbon and water production from different production zones/sections in a hydrocarbon reservoir and/or an injection well and detection of different phenomena, the method comprising: placing specific tracers with unique characteristic for each zone in different zones of a formation, said tracers being chemically intelligent tracers, for releasing tracers as a result of a specific event; chemically immobilizing the tracers in said zones to secure the tracers therein to obtain technical information from each zone, wherein placing and securing the tracers in the different zones of the formation by their securing or placing on a filter, a well fastening or a structure surrounding the well in each zone, and the chemical immobilization of a tracer being carried out by means of at least one polymer; detecting the tracers downstream so as to provide information about the different zones. 2. The method according to Claim 1, using at least one polymer capable of adhering to either the formation or the well completion, said tracers being either covalently linked or linked by ionic interactions to the polymer, or being contained in a polymer matrix; 3. The method according to any one of Claims 1, 2, further comprising placing and securing the tracers in the different zones by their injecting, pressing or other techniques. 4. The method according to any one of Claims 1 to 3, further comprising using chemical fluid intelligent tracers, the tracers being released upon contact with either an oil, gas or water flow. 5. The method according to any one of Claims 1 to 4, further comprising using different perfluorated hydrocarbons encapsulated in polymer matrixes or particles, the matrixes or particles being sensitive to water and hydrocarbons, respectively, as chemical fluid intelligent tracers. 6. The method according to any one of Claims 1 to 5, further comprising releasing the tracers from the polymer by breaking the binding between the polymer and the tracer. 7. The method according to any one of Claims 1 to 5, further comprising releasing the tracers from the polymer by breaking the polymer, resulting in small oligomers or chemicals containing tracers in the production stream. 8. The method according to Claim 7, further comprising controlling the degradation of polymer particles by using specially defined cross-linkers, the cross-linkers being modified so as to be sensitive towards specific events. 9. The method according to Claim 8, wherein the specific events used include pH, temperature, water or special chemicals added to the zones. 10. The method according to any one of Claims 1 to 9, wherein the tracer used is an oligonucleotide with special functional groups. 11. The method according to any one of Claims 1 to 10, further comprising performing short time and/or long time monitoring of the different zones in the hydrocarbon reservoir by using a first group of tracers released over a short period of time and a second group of tracers released gradually over a long period of time, respectively. 12. The method according to any one of Claims 1 to 10, further comprising monitoring sudden events occurring in the different zones in the hydrocarbon reservoir by using tracers, the tracers being released suddenly in response to changes in the local surroundings of the tracer. 13. The method according to any one of Claims 1 to 12, wherein the tracers comprise fluorescent, phosphorescent, magnetic particles or fluids, colored particles, DNA or microorganisms. 14. The method according to any one of Claims 1 to 13, further comprising isolating and/or detecting the tracers by optical, spectroscopic, chromatographic, acoustic, magnetic, capacitive, PCR of microwave techniques, or by any combination of these techniques. 15. The method according to any one of Claims 1 to 14, wherein the events to be detected include such as local variations in pH, salinity, hydrocarbon composition, temperature, pressure, microorganisms, and a difference between water produced in the formation and water injected from the different zones. 16. A method of monitoring hydrocarbon and water production from different production zones/sections in a hydrocarbon reservoir and/or an injection well and detection of different phenomena, the method comprising: placing specific tracers with unique characteristic for each zone in different zones of a formation, said tracers being chemically intelligent tracers, for releasing the tracers as a result of a specific event; chemically immobilizing the tracers in said zones to secure the tracers therein to obtain specific information from each zone; injecting specific triggers into the formation through an injection system for releasing the tracers; and detecting the tracers downstream so as to provide information about the different zones. 17. A method of monitoring hydrocarbon and water production from different production zones/sections in a hydrocarbon reservoir and/or an injection well and detection of different phenomena, the method comprising: placing specific tracers with unique characteristic for each zone in different zones of a formation, said tracers being chemically intelligent tracers, for releasing the tracers as a result of a specific event; chemically immobilizing the tracers in said zones to secure the tracers therein to obtain specific information from each zone; and detecting the tracers downstream so as to provide information about the different zones, accompanied by detecting the presence of the microorganisms in the different zones by using different fluorogenic and/or chromogenic enzyme substrates as tracers, the substrates and their fluorogenic/chromogenic part being cleaved by extracellular enzymes produced by the microorganisms in the reservoir.