... greater reduction in diffusion length resulting from the large increase in Sigma due to the increase in salinity. Figure 14. Slowing down, migration and diffusion length vs. salinity in a 30-pu SiO2 formation. The apparent porosity can be computed by referencing the data to a calibration condition. We...

...) where D and N are density and neutron apparent porosities, respectively. Mao (2001) studied the correlation characteristics of D and N for distinct identification of oil- and gas-saturated zones. Spears (2006) applied lithofacies-based porosity corrections derived from neutron-density cross-plots...

... logging thermal-neutron porosity measurement porosity measurement neutron porosity apparent porosity absorption effect neutron thermal neutron Upstream Oil & Gas modeling detector count rate salinity log analysis detector spwla 51 epithermal Symposium count rate porosity absorber...

... to errors in the computation of porosity, a key formation evaluation parameter. log analysis gas reservoir Upstream Oil & Gas spwla 51 well logging epithermal neutron porosity Symposium evaluation saturation fracture apparent porosity anhydrite China spectroscopy resistivity...

...) ballooning; and other costly problems. Section 6 discusses an error biasing technique and suggests that effects of errors in the resistivity-specific models, including the CEC model, can be minimized by biasing the models to result in low apparent porosity values. One can apply DDDD SPWLA 49th Annual Logging...

... the proper ratio-porosity transform. Then, environmental corrections are applied to the apparent porosity to determine the corrected formation porosity. Standard corrections usually include: 1. 2. 3. 4. 5. 6. Borehole size, borehole fluid salinity, and casing/cement corrections, which are normally combined...

... tank. The apparent porosity is determined from the calibrated ratio and the appropri- ate matrix transform. Fig. 5 shows the tool response in clean limestone, sandstone, and dolomite formations. Fig. 6 shows the tool response in typical sandstone and dolomite formations. This is based on the assumption...

... log analysis drilling fluids and materials apparent porosity porosity drilling fluid selection and formulation drilling fluid formulation capture cross section salinity drilling fluid chemistry drilling fluid property Neutron Instrument formation salinity effect Symposium correction...

... well logging temperature increase pressure correction dual-spaced thermal neutron apparent porosity Efficiency porosity Symposium Upstream Oil & Gas characteristic length neutron thermal neutron Temperature Effect temperature correction cross section fluid density diffusion length...

... to the primary API limestone porosity standards at the University of Houston has been established. log analysis apparent porosity consistency control system Neutron Instrument repeatability diameter hydrogen index gravity well logging central tube experiment instrument Symposium hydrogen...

... log analysis apparent porosity density 2 composition coefficient regression calculation excavation effect input data porosity response limestone well logging montmorillonite sandstone scale porosity ratio porosity response Upstream Oil & Gas absorber quartz neutron...

... analysis detector calibration apparent porosity natural rock well logging accuracy neutron investigation porosity chemical analysis cross-section test pit programme trace element Symposium tank Upstream Oil & Gas calculation experiment establishment physics Winfrith SPWLA...

... Upstream Oil & Gas apparent porosity porosity hydrogen index log analysis detector gin cc migration length well logging calculation volumetric porosity tool response hydrocarbon Porosity effect Symposium carbon density crude oil cross section experiment hydrogen density...

.... The sensitivity of tool response to bed thickness is also investigated. well logging cnt-g tool response bed boundary porosity estimate Symposium log analysis detector sensitivity Porosity profile tool response apparent porosity calculation porosity boundary Upstream Oil & Gas bed...

.... Upstream Oil & Gas neutron density experiment hydrogen density invasion well logging fresh water borehole neutron tool correction apparent porosity Spwla Sixteenth neutron investigation log analysis detector sonde saturation depth apparent bulk density porosity Symposium count rate...

... indicator Spwla Twelfth Neutron log porosity control fracture apparent porosity boron compound Symposium acoustic log Neutron Lifetime log cross section invasion permeability SPWLA TWELFTH ANNUAL LOGGING SYMPOSIUM, MAY 2-5, A NEW QUALITATIVE PERMEABILITY INDICATOR By C. P. Engelke and D. W...

... 30.71 35.41 2050-2070.5 46.59 Apparent porosity, percent 2.338 2.265 3 2.139 2.110 1 2.212 2.103 5 2.302 2.222 3 2.283 2.222 3 2.210 2.126 4 2.292 2.221 3 2.280 2.186 4 2.483 2.278 8 2.351 2.243 5 2.116 2.001 5 2.037 1.994 2 2.043 1.971 4 1.984 1.946 2 2.147 2.011 6 2.094 1.966 6 2.020 1.866 8 1.888...

... systems has been the merg- ing of data from an Induction-Electrical Survey with that from either a Sonic or a Formation Density Log. The resulting Formation Analysis Log consists of continuous curves of Rwa, FR /FS (or FR /FD), and apparent porosity. The location of potential pay zones is more easily...