Toyohiko Yamazaki

Possibility of CO2 sequestration into coal seams in Japan

Publisher Summary Carbon dioxide (CO2) sequestration into coal seams is one of the favored options for reducing atmospheric CO2 emissions from power and industrial plants. The recent systematic exploration of oil and natural gas revealed that huge volumes of coal seams lie deep in Paleogene sedimentary basins along the Japanese islands. Deep coal and coaly shale are noticed as the source rocks of natural gas and oil. In the central Hokkaido, unmineable coal seams deeper than 1,200m and shallower than 3000m are found to reach as much as 100 Gtons that may store 3.5 Gtons of CO2 and contain nearly 900Gm3 of coalbed methane. Coal-bearing Paleogene sedimentary basins spread widely offshore of the Honshu and Kyusyu islands. CO2 sequestration potential of deep unmineable coal seams in Japan would reach well past 10 Gtons. Huge volumes of deep unmineable coal seams may not only provide potential sinks for CO2 but also unseen enormous energy resources.

Effect of ionization on polymer solution viscosity.

In this paper, effect of ionization of polymer on viscosity of polymer solution is investigated theoretically from the microscopic view point.Flory-Fox relation, which simulates dependence of viscosity of polymer solution on radius of gyration of polymer molecule, is extended to apply for ionized polymer solution. Size of ionized polymer molecules in solution was defined by the electrical balance between the repulsive force of fixed ions of polymer particles and the neutralization by free ions clustered as an ionic atmosphere around polymer ion. A simple model equation is introduced to express the effects of salt ion concentration in solvent and of polymer ion concentration on viscosity of polymer solution.Measured viscosity values of the ionic polymer solutions are well matched with those derived by the introduced model equation, and microscopic observation of polymer molecules in solution turned out to assist better understanding of polymer rheology.

Quantitative Analysis of Density Vibration of Polymer Solution Flowing through Porous Media.

In this paper, vibration theory of elastic body is applied as an analogy to the quantitative analysis of resistance factor of polymer solution measured when it flows through porous media.Resistance against flow of polymer solution through porous media is not caused only by viscosity of polymer solution, but also affected by the energy dissipation by experiencing rarefaction and compression of polymer solution while flowing alternately in the throat connecting pores and in the open pore spaces. Euler Equation is modified to express such elastic resistance of polymer solution caused by the oscillation of normal stress in the fluid. Flow equation comprised of both Euler Equation and Darcy Equation is introduced to calculate both elastic and viscous resistances against flow through porous media. New equation is applied successfully to demonstrate the dilatant flow behavior of polymer solution in the flooding experiences through a capillary tube packed by glass beads and through Berea sand cores.Diffusion equation modified to express the vibration effect of viscoelastic fluid is applied to solve the pressure loss of polymer solution flowing through porous media. Quantitative analysis of the resistance factor of flow of polymer solution through porous media is presented by the use of analytical solution of diffusion equation.

On the Present Condition of Steam Soak and Flooding in Riaohe Oil Field in China.

This paper is an excursion report to get the information of steam injection operations to recover the heavy oil from deep formations in Riaohe oil field. Riaohe oil field is located in the sourthern district of north-eastern China, surrounded by the area from west side of Shenyang to Bohei along the Riaohe river. The central office of this oil firld is very convenient to be able to arrive within 4 hour drive through the high way from Luda.We discussed the steam injection and recovery processing tecnology with chinese researchers of the oil field during the excursion.In this paper, general geology of Riaohe oil field was descrived. Heavy oil recovery operations of two oil fields, Gaosheng and Shugang, were introduced, specially on reservoir and fluid properties, steam injection well completion, injection water preparation, control of generated steam quality and production facilities etc..