Samples are collected from a first wellbore and a second wellbore. Genetic material is extracted from the samples and analyzed to determine microorganisms present in subsurface geological features through which the first wellbore and the second wellbore pass. Movement of microorganisms originating in subsurface geological features at the location of the first wellbore to subsurface geological features at the location of the second wellbore can indicate movement of a carbon-based gas between the first wellbore and the second wellbore.

A method for onsite bacteria testing for oil and gas applications including collecting at least one component of a wellbore fluid; exposing at least one contaminant in the at least one component to at least one substrate that produces a detectable moiety; and performing a quantitative or qualitative detection of the detectable moiety.

A method for onsite bacteria testing for oil and gas applications including collecting at least one component of a wellbore fluid; exposing at least one contaminant in the at least one component to at least one substrate that produces a detectable moiety; and performing a quantitative or qualitative detection of the detectable moiety.

A method for detecting dog-fecal contamination in a sample, comprising assaying the sample using a nucleotide sequence based genetic assay which comprises contacting the sample with at least one nucleic acid molecule having the nucleic acid sequence shown in SEQ ID NO: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, the nucleic acid sequence being capable of binding to a nucleic acid sequence in the sample, and detecting binding of the nucleic acid molecule to the nucleic acid sequence in the sample, wherein a presence of binding is indicative of the presence of dog-fecal contamination in the sample; the nucleic acid molecules; and a kit comprising at least two of the above-described nucleic acid molecules.

An abundance of specific species of phytoplankton in a phytoplankton group in which a plurality of kinds coexists is calculated in a simple manner. Based on a reference sample intensity ratio r.sub.0, a reference sample total fluorescence intensity I.sub.0, and an existing quantity K.sub.0 of specific species of phytoplankton, an intensity ratio r.sub.d of other species of plankton is calculated. An analysis sample that is expected to have similarity with the reference sample is irradiated with the excitation light, an intensity of fluorescence emitted from the analysis sample is measured in each of wavelength bands A and B, and an intensity ratio r is calculated. A total fluorescence intensity I is measured, and an existing quantity K of the specific species of the phytoplankton is calculated based on the intensity ratio r.sub.d of other species of plankton, the intensity ratio r, and the total fluorescence intensity I.

A biocide testing system includes test columns, a bypass tube, control valves, and a control system. Each test column includes biocide test coupons. The bypass tube is fluidly coupled to each of the test columns. Each control valve is coupled between a respective test column and the bypass tube. The control system performs operations including: controlling the control valves to fluidly couple the test columns to a water source; controlling a pump to circulate water from the water source into the test columns to immerse each test coupon in water; controlling the control valves to fluidly isolate the test columns from the water source and to fluidly isolate each test column from the other test columns; controlling a particular control valve to fluidly couple a particular test column to a biocide source; and controlling the pump to circulate biocide from the biocide source into the particular test column to immerse the test coupons in the particular test column in biocide.

A biocide testing system includes test columns, a bypass tube, control valves, and a control system. Each test column includes biocide test coupons. The bypass tube is fluidly coupled to each of the test columns. Each control valve is coupled between a respective test column and the bypass tube. The control system performs operations including: controlling the control valves to fluidly couple the test columns to a water source; controlling a pump to circulate water from the water source into the test columns to immerse each test coupon in water; controlling the control valves to fluidly isolate the test columns from the water source and to fluidly isolate each test column from the other test columns; controlling a particular control valve to fluidly couple a particular test column to a biocide source; and controlling the pump to circulate biocide from the biocide source into the particular test column to immerse the test coupons in the particular test column in biocide.

The present invention relates to systems and methods for well planning and management in a field to maximize the production of hydrocarbons. Specifically, the present invention involves identifying microbial compositions (including phenotypic microbial compositions) of solid samples, such as cuttings or core samples, or fluid samples, such as produced or injected fluids and determining well communication or fracture height (frac height). With well communication and/or frac height analysis using microbial compositions, the operator can better plan the placement and geometry of wells in a field to maximize production and reduce the number of wells that need to be drilled to maximize that production.

Provided is a method for detecting and counting the relative content of a microorganism, comprising: adding a redox indicator to a growth medium to produce an indicating growth medium; the range of color variation of the redox indicator comprising three or more colors that can be easily recognized by the naked eye; diluting a sample to be tested, configuring multiple degrees of dilution, configuring multiple parallels for each degree of dilution, and growing the diluted test sample using the indicating growing medium; reading the color or absorbance of the indicating growth medium while growing and/or when growing is completed; and producing the relative content of a microorganism in the test sample on the basis of the level of color variation or the value of absorbance variation of the indicating growth medium.

Provided is a method for detecting and counting the relative content of a microorganism, comprising: adding a redox indicator to a growth medium to produce an indicating growth medium; the range of color variation of the redox indicator comprising three or more colors that can be easily recognized by the naked eye; diluting a sample to be tested, configuring multiple degrees of dilution, configuring multiple parallels for each degree of dilution, and growing the diluted test sample using the indicating growing medium; reading the color or absorbance of the indicating growth medium while growing and/or when growing is completed; and producing the relative content of a microorganism in the test sample on the basis of the level of color variation or the value of absorbance variation of the indicating growth medium.