Oil and Gas Well Fracture Liquid Tracing Using DNA

摘要

Tracing fracking liquid in oil and gas wells using unique DNA sequences. For each of the DNA sequences, bonding to magnetic core particles, and encapsulating them with silica. Pumping the volumes of fracking liquid, each marked with one of the unique DNA sequences, into the well. Pumping fluids out of the well while taking fluid samples. For each of the plural fluid samples, gathering the silica encapsulated DNA using magnetic attraction with the magnetic core particles, dissolving away the silica shells, thereby separating the plural unique DNA sequences form the magnetic core particles, and analyzing the concentration of the unique DNA sequences in each of the plural fluid samples. Then, calculating the ratio of each of the volumes of fracking liquid recovered for each of the fluid samples, and thereby establishing the quantity of the volumes of fracking liquids removed from the fracture zones.

主权项

1. A method of tracing fracking liquid in oil or gas bearing formations using plural unique DNA sequences as fluid markers, comprising the steps of:
a) for each of the plural unique DNA sequences, encapsulating one of the plural unique DNA sequence within tracing particles, which range in size between 1 nm and 10 μm, by;
1) providing particle cores having magnetic components therein;2) encapsulating the particle cores and the one of the plural unique DNA sequences by depositing a silicon compound shell about the particle cores, thereby producing encapsulated DNA particles; b) pumping the plural volumes of fracking liquid, each marked with a predetermined quantity of unique ones of the encapsulated DNA particles, into the formation, thereby defining plural fracture zones; c) pumping fluids out of the formation while taking plural well fluid samples; d) for at least one of the plural well fluid samples;
1) gathering and concentrating plural encapsulated DNA particles from the at least one of the plural well fluid samples using magnetic attraction with the magnetic components in particle cores;2) dissolving the silicon compound away from the magnetic components in the plural encapsulated DNA particles using a solution comprising hydrofluoric acid, thereby placing the plural unique DNA sequences into the solution;3) measuring the quantity of each of the plural unique DNA sequences in the solution; e) determining ratios of the plural volumes of fracking liquid recovered in the at least one of the plural well fluid samples based on the quantity of the plural unique DNA sequences in the solution.