A system and method identify hydrocarbon productive reservoir zones using Monte Carlo numerical analysis to account for uncertainties in log measurements and petrophysical parameters. Random errors in logging tool responses and core measurements, as well as reservoir heterogeneity, are incorporated in a Monte Carlo simulation to output appropriate petrophysical models to calculate statistical distributions for saturation and permeability to define productive zones, non-productive zones and zones of undetermined productivity as a basis of deciding whether additional logging, core sampling or well test data are needed to reclassify the undetermined zones as either productive or non-productive. As uncertainties are quantified in the analysis, the degree of certainty in determining productive and non-productive zones is known and can be used to decide whether to further test, stimulate or abandon reservoir zones.

Monte carlo simulation of well logging data

A method of determining the porosity and fluid saturation for a given volume of an underground formation through which a borehole is drilled, the method comprising: measuring, from within the borehole, parameters relating to characteristics of the underground formation; determining volumetric values for resistivity, hydrogen index, density and neutron capture cross-section for the given volume from the measured parameters, each volumetric value including a contribution from formation matrix, water, oil and gas; determining, from the volumetric values, the volumes of rock matrix, pore water, oil and gas, and the salinity of the pore water; and determining the porosity and fluid saturation of the volume of the formation from the determined volumes and salinity.

Determination of porosity and fluid saturation of underground formations

Formation evaluation measurements are used to estimate formation lithology. The estimated lithology is used to provide an estimate of acoustic wave slowness. The estimated acoustic wave slowness is used to provide processing parameters for acoustic data that are less sensitive to noise.

Petrophysics-guided processing of lwd acoustic data

A method for predicting fluid flow is provided. An exemplary embodiment of the method comprises obtaining data describing a stratigraphy, the stratigraphy comprising a fault, predicting a volume of shale in the fault and calculating a thickness of the fault. The exemplary method may also comprise calculating a permeability of the fault based on the volume of shale, the thickness, an estimated shale smear continuity factor and an estimated cataclastic reduction factor. The exemplary method may additionally comprise predicting fluid flow in a subsurface region based on the fault permeability.

Method for predicting fluid flow

An apparatus and method for estimating a parameter of interest of an earth formation. An apparatus includes an elongated support member; a primary transmitter on the elongated support member; and a receiver toroid on the elongated support member, the receiver toroid being positioned transversely on the elongated support member and including a single coil antenna. Methods include positioning a logging tool in a borehole in the earth formation; using a transverse receiver toroid on an elongated support member on the logging tool, wherein the transverse receiver toroid includes a single coil antenna; and producing a signal responsive to an electrical signal produced by a primary transmitter.

Image enhancement for resistivity features in oil-based mud image

Measurements made with porosity and density logging tools in a gas reservoir may differ due to invasion effects. The effects are particularly large on measurement-while-drilling applications where invasion is minimal. Using a Monte-Carlo method, a relationship is established between true formation porosity and porosity estimates from density and porosity tools. This relationship is used on real data to get an improved estimate of formation porosity and of gas saturation.

Guo Pingjun

Papers

Method for determining formation porosity and gas saturation in a gas reservoir