Saudi Arabian Oil Company

Quan Chen

Ali Abdallah Al-Yousef

Sultan Muhammad Al Enezi

Subhash Chandrabose Ayirala

Sultan M Enezi

A method for determining properties of different cation exchange sites in a rock core sample, at a preserved state of the rock core sample may include providing a rock core sample that includes a plurality of indigenous exchangeable cations adsorbed onto the cation exchange sites, a plurality of cation exchange sites occupied by a crude oil, and one or more fluids occupying pore spaces in the rock core sample; subjecting the rock core sample to a plurality of coreflooding steps, the plurality of coreflooding step displacing the plurality of indigenous exchangeable cations, the crude oil, and the one or more fluids in at least three separate coreflooding steps to render the rock core sample clean of native components; determining an amount of indigenous exchangeable cations adsorbed onto the cation exchange sites; subjecting the rock core sample clean of native components to a plurality of coreflooding steps to determine a total amount of exchangeable cations adsorbed onto the cation exchange sites when the rock core sample is clean of native components; and determining at least one property of different cation exchange sites in the rock core sample at the preserved state based on the amount of indigenous exchangeable cations and the total amount of exchangeable cations.

Methods of determining cation exchange sites occupied by crude oil and the wettability of cation exchange sites in rock core samples in a preserved state

A method for determining properties of different cation exchange sites in a rock core sample at a non-preserved state may include displacing all native components out of the rock core sample before subjecting the rock core sample to coreflooding steps to determine a total amount of exchangeable cations adsorbed onto the cation exchange sites; injecting formation brine and then a reservoir crude oil into the rock core sample such that the rock core sample includes indigenous exchangeable cations adsorbed onto the cation exchange sites, cation exchange sites occupied by a crude oil, and one or more fluids; subjecting the rock core sample to coreflooding steps to displace the indigenous exchangeable cations, the crude oil, and the one or more fluids; determining an amount of indigenous exchangeable cations adsorbed onto the cation exchange sites; and determining at least one property of different cation exchange sites.

Methods of determining cation exchange sites occupied by crude oil and the wettability of cation exchange sites in rock core samples in a non-preserved state

A method for determining residual fluid saturation of a subsurface formation includes acquiring a sample of the subsurface formation, determining a first residual oil saturation during a water flooding process, determining a second residual oil saturation during a gas flooding process, determining a third residual oil saturation during an enhanced oil recovery (EOR) processes, and determining irreducible water saturation during an oil displacing water process.

Methods and systems for determining residual fluid saturation of a subsurface formation

A method for determining properties of different cation exchange sites in a rock core sample may include providing a rock core sample that is in either a preserved state or a non-preserved state, wherein a preserved form of the rock core sample includes a plurality of indigenous exchangeable cations adsorbed onto the cation exchange sites, a plurality of cation exchange sites occupied by a crude oil, and one or more fluids occupying pore spaces in the rock core sample; subjecting the rock core sample to a plurality of coreflooding steps, the plurality of coreflooding step displacing the plurality of indigenous exchangeable cations and the one or more fluids in at least two separate coreflooding steps to render the rock core sample clean of indigenous exchangeable cations; and determining an amount of indigenous exchangeable cations adsorbed onto the cation exchange sites.

Methods of determining cation exchange sites in rock core samples

A primary drainage process, a core aging process, a spontaneous water imbibition process, a forced water imbibition process, a spontaneous hydrocarbon imbibition process, and a secondary drainage process is conducted on a rock sample. For each of the primary drainage process, the spontaneous water imbibition process, the forced water imbibition process, the spontaneous hydrocarbon imbibition process, and the secondary drainage process, a pressure distribution and a fluid saturation distribution are measured across multiple locations along the rock sample. For each of the locations, the pressure distribution and the fluid saturation distribution are combined to produce a capillary pressure bounding curve and scanning loop for the rock sample, and a relative permeability bounding curve and scanning loop are determined at least based on the measured fluid saturation and pressure distributions at the respective location. A wettability distribution along the rock sample is determined based on the bounding curves and scanning loops.

Determination of scanning loops of capillary pressure and relative permeability curves and wettability distribution of rock samples

A core sample holder assembly for performing core flood experiments includes a first end cap having a first cylindrical body with a first central chamber and a first inner end that is ring shaped, and a second end cap having a second cylindrical body with a second central chamber and a second inner end that is ring shaped. Three flow lines are spaced elevationally apart, the three flow lines extending from a first outward end to a first inward facing surface of each end cap. A flexible sleeve circumscribes the first end cap and the second end cap. A test sample bore is defined by the first inner end, the second inner end, and an inner diameter surface of the flexible sleeve. A central axis extends through the first end cap, the second end cap, and the flexible sleeve, the first end cap, the second end cap, and the flexible sleeve being axially aligned.

Device and process for maintaining zero capillary pressure boundary condition during core flood experiments

A primary drainage process, a core aging process, a water flooding process, an enhanced oil recovery (EOR) flooding process, and a core cleaning process is conducted on a rock sample. For each of the primary drainage process, core aging process, water flooding process, EOR flooding process, and core cleaning process, an equilibrium sample magnetization distribution and a spatially resolved spin-spin relaxation time spectrum are measured across multiple locations along a longitudinal length of the rock sample. One or more hydrocarbon saturation distributions of the rock sample are determined based on the equilibrium sample magnetization distributions. One or more wettability distributions of the rock sample are determined based on the spatially resolved spin-spin relaxation time spectrums and the one or more hydrocarbon saturation distributions. One or more wettability modification factor distributions of the rock sample are determined based on the spatially resolved spin-spin relaxation time spectrums and the hydrocarbon saturation distribution(s).

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Al Khobar, Saudi Arabia

Quan Chen