High-Accuracy Oriented Perforating Extends Sand-Free Production Life of Andrew 
Field

Martin, Alison; Robertson, D. H.; Wreford, John; Lindsay, Angus

doi:10.2523/93639-ms

Cited by 3 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This example concerns a Paleocene sandstone dome located in the Central North Sea (Martin et al, 2005). The examined depth zone contains an oil-saturated column with a gravity of 40°API underlain by an active aquifer (BP, 2003).…”

Section: Field Example No 2: Central North Sea Sandstonementioning

confidence: 99%

Estimation of dynamic petrophysical properties of water-bearing sands invaded with oil-base mud from the interpretation of multiple borehole geophysical measurements

Heidari

Torres‐Verdín

2012

GEOPHYSICS

View full text Add to dashboard Cite

Nonmiscible fluid displacement without salt exchange takes place when oil-base mud (OBM) invades connate watersaturated rocks. This is a favorable condition for the estimation of dynamic petrophysical properties, including saturationdependent capillary pressure. We developed and successfully tested a new method to estimate porosity, fluid saturation, permeability, capillary pressure, and relative permeability of waterbearing sands invaded with OBM from multiple borehole geophysical measurements. The estimation method simulates the process of mud-filtrate invasion to calculate the corresponding radial distribution of water saturation. Porosity, permeability, capillary pressure, and relative permeability are iteratively adjusted in the simulation of invasion until density, photoelectric factor, neutron porosity, and apparent resistivity logs are accurately reproduced with numerical simulations that honor the postinvasion radial distribution of water saturation. Examples of application include oil-and gas-bearing reservoirs that exhibit a complete capillary fluid transition between water at the bottom and hydrocarbon at irreducible water saturation at the top. We show that the estimated dynamic petrophysical properties in the water-bearing portion of the reservoir are in agreement with vertical variations of water saturation above the free waterhydrocarbon contact, thereby validating our estimation method. Additionally, it is shown that the radial distribution of water saturation inferred from apparent resistivity and nuclear logs can be used for fluid-substitution analysis of acoustic compressional and shear logs.

show abstract

Section: Field Example No 2: Central North Sea Sandstonementioning

confidence: 99%

Estimation of dynamic petrophysical properties of water-bearing sands invaded with oil-base mud from the interpretation of multiple borehole geophysical measurements

Heidari

Torres‐Verdín

2012

GEOPHYSICS

View full text Add to dashboard Cite

show abstract

“…The first field example is a sandstone dome structure of Paleocene age that is located in the Central North Sea (Martin et al, 2005;Salazar et al, 2007). Nearcontinuous sandstone bodies were formed by overlapping submarine fans during the early The formation under analysis (B1/B2 sands) is predominantly composed of noncalcareous, blocky and sandy high-density gravity-flow deposits interbedded with gray mudstones.…”

Section: Reservoir Backgroundmentioning

confidence: 99%

Geophysics Dissertation Abstracts

2013

GEOPHYSICS

View full text Add to dashboard Cite

GEOPHYSICS publishes abstracts of dissertations and titles of master's theses both in print and online. Recent graduates are invited to submit their abstracts or titles by completing and submitting the appropriate form found at http://seg.org/ dissertationabstracts. Abstracts and titles will be reviewed and accepted or rejected based on their relevance to the readers of Geophysics. Abstracts must be written in English and defended in 2009 or later.Reservoir description with well-log-based and core-calibrated petrophysical rock classification Chicheng Xu, The University of Texas at Austin Month and year defended: July 2013Bimodal log-normal pore-size distribution functions derived from mercury injection capillary pressure (MICP) data are first introduced to characterize complex pore systems in carbonate and tight-gas sandstone reservoirs. Six pore-system attributes are interpreted and integrated to define petrophysical orthogonality or dissimilarity between two pore systems. A simple 3D cubic pore network model constrained by nuclear magnetic resonance (NMR) and MICP data is developed to quantify fluid distributions and phase connectivity for predicting saturation-dependent relative permeability during two-phase drainage.There is rich petrophysical information in spatial fluid distributions resulting from vertical fluid flow on a geologic time scale and radial mud-filtrate invasion on a drilling time scale. Log attributes elicited by such fluid distributions are captured to quantify dynamic reservoir petrophysical properties and define reservoir flow capacity thereby. A new rock classification workflow that reconciles reservoir saturation-height behavior and mud-filtrate for more accurate dynamic reservoir modeling is developed and verified in both clastic and carbonate fields.Rock types vary and mix at the sub-foot scale in heterogeneous reservoirs due to depositional control or diagenetic overprints. Conventional well logs are limited in their ability to probe the details of each individual bed or rock type as seen from outcrops or cores. A bottom-up Bayesian rock typing method is developed to efficiently test multiple working hypotheses against well logs to quantify uncertainty of rock types and their associated petrophysical properties in thinly bedded reservoirs. Concomitantly, a top-down reservoir description workflow is implemented to characterize intermixed or hybrid rock classes from flow-unit scale (or seismic scale) down to the pore scale based on a multiscale orthogonal rock class decomposition approach.Correlations between petrophysical rock types and geologic facies in reservoirs originating from deltaic and turbidite depositional systems are investigated in detail. Emphasis is placed on the cause-and-effect relationship between pore geometry and rock geologic attributes such as grain size and bed thickness. Well-log responses to those geologic attributes and associated pore geometries are subjected to numerical log simulations. Sensitivity of various physical logs to petrophysical orthogonality betw...

show abstract

“…The field case considered in this work corresponds to a Paleocene sandstone dome located in the Central North Sea (Martin et al, 2005). The field comprises an average of 60 m of a gas cap with a gas/oil ratio of 871 scf/bbl and 58 m of an oil-saturated column with a gravity of 40 o API followed by an active aquifer (BP, 2003).…”

Section: Geological Description and Depositional Systemmentioning

confidence: 99%

Fluid Density and Viscosity Effects on Borehole Resistivity Measurements Acquired in the Presence of Oil-Based Mud and Emulsified Surfactants

Salazar

Malik

Torres‐Verdín

et al. 2007

SPE Annual Technical Conference and Exhibition

View full text Add to dashboard Cite

fax 01-972-952-9435. AbstractWe quantify the influence of oil-base mud-filtrate invasion and formation fluid properties on the spatial distribution of fluid saturation and electrical resistivity in the near-wellbore region. The objective is to appraise the sensitivity of borehole resistivity measurements to the spatial distribution of fluid saturation resulting from the compositional mixing of oil-base mud (OBM) and in-situ hydrocarbons.First, we consider a simple two-component formulation for the oil phase (OBM and reservoir oil) wherein the components are first-contact miscible. A second approach consists of adding water and surfactant to a multi-component OBM invading a formation saturated with multiple hydrocarbon components. Simulations also include presence of irreducible, capillary-bound, and movable water. The dynamic process of OBM invasion causes component concentrations to vary with space and time. In addition, the relative mobility of the oil phase varies during the process of invasion because oil viscosity and oil density are both dependent on component concentrations.Presence of surfactants in the OBM is simulated with a commercial adaptive-implicit compositional formulation that models the flow of three-phase multi-component fluids in porous media. Simulations of the process of OBM invasion yield two-dimensional spatial distributions of water and oil saturation that are transformed into spatial distributions of electrical resistivity. Subsequently, we simulate the corresponding array-induction measurements assuming axialsymmetric variations of electrical resistivity.We perform sensitivity analyses on field measurements acquired in a well that penetrates a clastic formation and that includes different values of density and viscosity for mudfiltrate and formation hydrocarbon. These analyses provide evidence of the presence of a high-resistivity region near the borehole wall followed by a low-resistivity annulus close to the non-invaded resistivity region. Such an abnormal annulus is predominantly due to high viscosity contrasts between mudfiltrate and formation oil. The combined simulation of invasion and array-induction logs in the presence of OBM invasion provides a more reliable estimate of water saturation, which, in turn, improves the assessment of in-place hydrocarbon reserves.

show abstract

High-Accuracy Oriented Perforating Extends Sand-Free Production Life of Andrew Field

Cited by 3 publications

References 3 publications

Estimation of dynamic petrophysical properties of water-bearing sands invaded with oil-base mud from the interpretation of multiple borehole geophysical measurements

Estimation of dynamic petrophysical properties of water-bearing sands invaded with oil-base mud from the interpretation of multiple borehole geophysical measurements

Geophysics Dissertation Abstracts

Fluid Density and Viscosity Effects on Borehole Resistivity Measurements Acquired in the Presence of Oil-Based Mud and Emulsified Surfactants

Contact Info

Product

Resources

About