Saudi Arabian Oil Company

Yufeng Cui

Peng Lu

Kaiming Xia

Ming Lei Zhang

Hongwen Zhao

Wei Wei

Weihua Wang

Rainer Zuhlke

David Tang

Hasan Algheryafi

David Amendt

A method for hydrocarbon production from a carbonate formation includes receiving a carbonate texture description of a drill cutting. A pre-defined grain fraction is assigned to the drill cutting based on the texture description. The pre-defined grain fraction is one of a set of pre-defined grain fractions and each pre-defined grain fraction of the set of pre-defined grain fractions corresponds to a respective one the set of carbonate texture descriptions. Based on the pre-defined grain fraction assigned to the drill cutting and a depth of the wellbore from which the drill cutting is taken, an estimated porosity of the drill cutting is determined using an algebraic equation, coefficients for which are determined by regression analysis using reference rock samples that have been assigned pre-defined grain fractions from the same set of pre-defined grain fractions.

Hydrocarbon exploration and production using porosity variation prediction based on carbonate texture

Systems and methods for determining optimal perforation orientations for hydraulic fracturing of wells in a subterranean formation are presented. The method comprises identifying in-situ stresses for a portion of a well bore formed and transforming the in-situ stresses between coordinate systems. Pressure coefficients and a breakdown pressure for each trial perforation phase angle at a perforation cluster determined, and a perforation point in the well bore coordinate system is calculated for each trial perforation phase angle of the perforation cluster. The perforation point in the well bore coordinate system is transformed to the translated global coordinate system for each trial perforation phase angle. A target perforation phase angle is selected at a minimum breakdown pressure for the perforation cluster, and a perforation azimuth and perforation dip is calculated for the perforation cluster at the minimum breakdown pressure for the target perforation phase angles.

Method and system to determine optimal perforation orientation for hydraulic fracturing slant wells

A system and method for performing a reservoir evaluation are disclosed. The method includes obtaining a nuclear magnetic resonance (NMR) dataset for a plurality of samples and obtaining an NMR log for a wellbore penetrating a reservoir. The method further includes determining a rock facies description for each sample, determining an NMR transverse relaxation time (NMR T) distribution from the NMR dataset, and determining a set of parameters characterizing the NMR Tdistribution based on one or more predetermined parameters. The method still further includes identifying a plurality of NMR facies based, at least in part, on the set of parameters for each sample, determining a transformation that maps a subset of rock facies to a subset of the plurality of NMR facies, and performing the reservoir evaluation based, at least in part, on applying the transformation to the NMR log.

Parameterization of nuclear magnetic resonance transverse relaxation time distribution

Techniques for hydraulic fracturing a subsurface formation can include using a deterministic model to simulate a deviated well comprising a casing and at least one perforation tunnel. The techniques can include determining a different statistical distribution for each of one or more parameters to the deterministic model. The statistical distributions can be determined from the log data along the measured depth within the wellbore. The techniques can include probabilistically solving the deterministic model to determine a mean and a standard deviation of breakdown pressures along the measured depth within the wellbore. The techniques can include processing the mean and the standard deviation of breakdown pressures to determine an upper bound breakdown pressure based on a level of confidence. The techniques can include drilling and completing a deviated well based on the determined upper bound breakdown pressure and injecting hydraulic fluid to cause hydraulic fracturing of the subsurface formation.

Fracturing a subsurface formation based on a probabilistic determination of the required breakdown pressure

Methods of estimating permeability of reservoir rocks using mercury injection capillary pressure can include: receiving mercury injection capillary pressure test data and porosity data for a core sample; determining a fractal dimension (D) for the core sample based on the received mercury injection capillary pressure test data for the core sample; determining a pore throat radius (R) for the core sample; determining a composite parameter (&#x3b2;) for the core sample where and estimating permeability (K) of the core sample based on a relationship of ln(K) as a function of ln(&#x3b2;) determined by performing a regression analysis data from other core samples from the reservoir.

Estimating permeability of reservoir rocks using mercury injection capillary pressure

A method of rock typing includes obtaining mercury injection capillary pressure (MICP) data regarding a region of interest. A distance matrix is computed for distributions determined from the MICP data using a statistical distance metric. A cluster tree of the distributions is generated using the distance matrix. The cluster tree is adjusted based on a petrographic characteristic to produce an adjusted cluster tree, which is used to determine a pore structure types of the region of interest.

System and method of typing heterogeneous reservoir rocks

Techniques for determining a breakdown pressure of a subterranean formation include identifying in-situ stresses for a portion of a wellbore formed into a subterranean formation; transforming the in-situ stresses (and induced stresses) from a global coordinate system to a wellbore coordinate system of a deviated portion of the wellbore that includes at least one perforation tunnel for a hydraulic fracturing treatment; transforming the in-situ stresses from the wellbore coordinate system to a perforation coordinate system through at least one rotation matrix; determining one or more stresses at a wellbore-perforation interface of the perforation tunnel from the in-situ stresses in the perforation coordinate system; calculating one or more hoop stresses at a perforation tunnel wall of the perforation tunnel from the determined stresses on the wellbore-perforation interface; and determining a breakdown pressure for the subterranean formation based on the calculated one or more hoop stresses and an effect of casing-cement-formation interaction.

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Beijing, China

Yufeng Cui