Effective pressure effect on porous reservoir formation is one of the most important factors contributing to time-lapse seismic attribute changes. Our research shows that the existing commonly used models tend to overestimate effective pressure effect at high effective pressure, which might cause significant misinterpretation of 4D seismic data. Based on analysis of a large quantity of lab data...

Tight sandstone reservoirs have smaller pore throats, complex structures, strong heterogeneity in the throat system, and significant differences fluid distribution. To reveal occurrence characteristics of movable fluids tight reservoirs, typical core samples from Chang 4+5 reservoir Upper Triassic Yanchang Formation Ordos Basin were selected micro classification standard was established by usin...

Reservoir characteristics and the occurrence mechanism of shale gas outside Sichuan Basin are research hotspots normally pressured shales in China. Taking on Anchang syncline from periphery as an example, X-ray diffraction, organic geochemistry, rock physical experiments were carried out to analyze reservoir their main geological controls shales. The mineralogical results show that studied main...

the main purpose of this investigation is to study the effect of near miscible co2 injection in different porous mediums on both lab and field scales. this effect can be traced by the change of two-phase gas-oil relative permeability curves. in this work, the experiments have been performed on three rock types (i.e. sandstone, dolomite, and artificial fractured sandstone) based on an incrementa...

Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypass (CPB) procedures. However, the negative pressure created in the closed cardiotomy reservoir can be transmitted to the oxygenator if a nonocclusive or centrifugal arterial pump is used, resulting in bubble transgression (BT) from the gas to blood compartment of the oxygenator. We analyzed the vacu...

We experienced two cases of lung injury resulting from fluted silastic drain extraction under reservoir-generated negative pressure suction. In the first case, a 67-year-old man underwent coronary artery bypass grafting. A 19 Fr BLAKE drain was placed at the pericardial cavity, the mediastinum, and the left thoracic cavity. All three drains were connected to J-VAC reservoirs. After removing the...

the mechanical aspect of entropy-exergy relationship, together with the thermal aspect usually consid-ered, leads to an extended formulation of physical exergy based on both maximum useful work and maximum useful heat that are the outcome of available energy of a thermodynamic system. this approach suggests that a mechanical entropy can be studied, in addition to the already used thermal entrop...

Finding a representative fluid in a hydrocarbon reservoir is crucial for integrated reservoir management. In this study, a systematic approach for screening and selecting consistent fluid samples in a reservoir was developed. The model integrated quality control (QC) of well conditioning before sampling, QC of PVT data, thermodynamic modeling and compositional gradient within a reservoir. Well ...

carbon dioxide flooding is considered to be one of the most effective enhanced oil recovery methods for the light oil reservoirs. depending on the operating pressure, the process might be miscible or immiscible. minimum miscibility pressure (mmp) is the most important parameter for assessing the applicability of any miscible gas flood for an oil reservoir. the miscibility condition is determine...

Long-term oil and gas exploitation in reservoir will lead to pore pressure depletion. The pore pressure depletion will result in changes of horizontal in-situ stresses both in reservoirs and caprock formations. Using the geophysics logging data, the magnitude and orientation changes of horizontal stresses in caprock and reservoir are studied. Furthermore, the borehole stability can be affected ...