Laboratory-scale Investigation of Two-phase Relative Permeability

We present experimental investigations of two-phase (oil and water) relative permeability of laboratory scale rock cores through a joint use of direct X-ray measurement and flow-through investigations. The study is motivated by the observation that appropriate modeling of oil and water displacement in porous media or fractured rocks requires to be firmly grounded on accurate and representative core flood experiments and their appropriate interpretation. Experimental data embed key information relating relative permeability to observables. In this context, direct measurement of in-situ fluid saturation through X-Ray techniques has the unprecedented ability to characterize key processes occurring during the displacement of immiscible fluids through natural permeable materials. Water saturation profiles determined by X-ray scanner can then be linked to relative permeability curves stemming from two-phase flow experiments. We illustrate the benefit of employing direct X-Ray measurements of fluid saturation through a set of laboratory experiments targeted to the estimate of two-phase relative permeabilities of homogeneous samples (sand pack and Berea sandston core). Data are obtained for a range of diverse fractional flow rates and provide information at saturations ranging from irreducible water content to residual oil saturation. Our X-Ray saturation data are consistent with an interpretation of measured relative permeabilities as associated with water-wet rock conditions. The comparison of different preamble samples result high displacement efficiency and recovery factor corresponds to the high permeable and well-connected pores

Use of X-Ray saturation measurements in flow-through investigations for the characterization of two- and three-phase relative permeability of carbonate rock

We illustrate the results of a suite of laboratory-scale experimental investigations of multi-phase (oil/ water/ gas) relative permeabilities. Two- and three-phase relative permeability data are obtained on a core of Portland limestone by way of a Steady-State (SS) technique. Our laboratory methodology allows improved relative permeability acquisition through a joint use of traditional flow-through investigations and direct X-Ray measurement of the core local saturation distribution. The latter renders detailed distributions of (section-averaged) fluid phases along the core, which can then be employed for the characterization of relative permeabilities. The three-phase Steady-State relative permeability experiments have been conducted by resorting to a dual energy X-Ray methodology. The experimental setup also includes a closed loop burette system to validate and support saturation measurements/estimates. The three-phase experiments are performed by following an IDI (Increasing- Decreasing - Increasing) saturation path. The study demonstrates the capability of the methodology to obtain reliable two- and three-phase data for model calibration and simulation

Secretion of lipoproteins, apolipoprotein A-I and apolipoprotein E by isolated and perfused liver of rat with experimental nephrotic syndrome.

Nephrotic syndrome induced in the rat by the administration of puromycin aminonucleoside is accompanied by a hyperlipoproteinemia characterized by an elevation of all plasma lipoproteins, particularly of VLDL (1.006 g/ml) and HDL1 (1.050-1.090 g/ml). The increase of HDL1 is due to the accumulation of a lipoprotein species floating mainly in the density interval 1.050-1.090 g/ml, in which apolipoprotein A-I replaces apolipoprotein E as the major constituent peptide. This lipoprotein has been designated nephrotic HDL. The present study was conducted to establish whether nephrotic liver secreted more lipoproteins than the control liver and, in addition, produced a lipoprotein similar to nephrotic HDL found in plasma. Isolated livers from control and nephrotic rats were perfused with a lipoprotein-free medium for 3 h in a recirculating system. Lipoproteins were isolated by ultracentrifugation; apolipoprotein A-I and apolipoprotein E were measured in the whole perfusate at various time intervals. Nephrotic liver secreted twice as much VLDL and HDL2 and 30% more LDL and HDL1 than the control liver. This was accompanied by an increased secretion of both apolipoprotein A-I and apolipoprotein E, the levels of which were 6.5- and 2-fold, respectively, of those found in the control perfusates at the end of the perfusion. In view of the increased secretion of apolipoprotein A-I, the apolipoprotein A-I to apolipoprotein E ratio was much higher in the perfusates of nephrotic livers than in those of the controls. The concentration of apolipoproteins A-I and E in plasma of nephrotic rats was 7- and 2-fold, respectively, of that found in the plasma of the controls. In the perfusates of the nephrotic livers, we could not find a HDL1 (1.050-1.090 g/ml) rich in apolipoprotein A-I similar to that isolated from plasma (nephrotic HDL). We suggest that the latter is formed in the circulation from the intravascular modification of HDL2 secreted in excess by the li

Bone invasion by Walker 256 carcinoma, line A in young and adult rats: effects of etidronate

Line A of Walker 256 carcinoma implanted in the muscle adjacent to the tibia of young (6 weeks) and adult (9 months) male rats invaded the bone. Osteolysis and reactive growth were greater in the bone of young animals than in adults. Ethane-1-hydroxy-1,1-bisphosphonate prevented bone lysis and tumor invasion of the cortex both in young and adult animals. This model may be useful for studies of age-related differences in tumor infiltration into the bone and for investigating drug effects on this process