Comprehensive tests on rising height of capillary water for coarse grained soil

According to the comprehensive tests on the rising height of capillary water for seven kinds of differ- ent coarse grained soil by use of the method of standpipe, the relationship between the rising height of capillary water and time was obtained, and the influencing factors and rules were analyzed. The data of the steady rising height of capillary water were obtained, and the regression equation of coarse grained soil on steady height and physical indexes （effective grain dl0 and porosity n） was found. Compared with Hazen＇s and other expressions that could estimate the steady height of capillary water of coarse grained soil, the proposed method is satisfactory and the defects of the latter were pointed out.

Experimental study on height simulation of capillary fringe

In this paper, the plexiglass experimental column was used to analyze the capillary fringe thickness of three kinds of lithologies-silty sand, silt and silty clay-providing a basis for defining the interface in the study of hydrodynamics at the water table between vandose water and groundwater. The capillary fringe generally refers to the subsurface layer in which the groundwater seeps up to the air-entry suction value due to capillary action, and is nearly saturated with water. The thickness of the capillary fringe varies with different lithologies. In this experiment, self-made stable water supply devices were used to study the height of capillary rise, capillary water volume and capillary fringe thickness of the three lithologies through capillary experiment and numerical simulation. Experimental results show as follows:(1) Rising height of capillary water is related to time, particle radius, volume, etc., and the relationship between height and time is in line with the Hill model.(2) The smaller the particle radius, the more water the pores contain, and the ratio of the unsaturated portion of capillary water to the total water content gradually rises. Experimental results obtained by numerical simulation, segmentation and actual measurement are consistent.(3) The thickness of the capillary zone is related to the lithology. The larger the particle size, the smaller the thickness of the capillary fringe, and vice versa. In silty sand, the thickness measures about 13 cm. The figure rises to 16 cm in silt, and 37 cm in silty clay. This work studies the law of soil water transport at saturated-unsaturated interface. Experimental results are of great significance to the study of soil water and salt transport and soil salinization control in unsaturated zone.

Study on Water Ridge Variation of Horizontal Wells in Bottom Water Reservoir

X oilfield is a typical strong bottom water reservoir in Bohai Sea. It is developed by single sand body horizontal well. The edge and bottom water of the reservoir is active and natural energy development mode is adopted. At present, the comprehensive water cut of the oilfield is more than 96%, and has entered the stage of high water cut oil recovery. At present, fluid extraction from old wells and new adjustment wells are the main ways to increase oil production. With the deepening of development, the distribution of underground remaining oil is becoming more and more complex. In order to further improve the implementation effect of adjustment wells, the study of residual oil distribution law is increasingly important, and the study of water ridge morphology of horizontal wells in bottom water reservoir has an important guiding role in the study of remaining oil distribution. The main contents of this paper are as follows: the influence of horizontal well spacing, vertical and horizontal permeability ratio, single well liquid production, vertical position of horizontal well, oil-water viscosity ratio, water cut and interlayer on water ridge morphology. These understandings can effectively guide the deployment and optimization of adjustment wells. It provides technical support for the prediction of watered out thickness and optimization of adjustment well layout scheme in X oilfield, and guides the further development and production of the oilfield.

RISING TO NEW HEIGHTS

The New China has undergone transformational economic and social changes in the last 60 years, bringing it into a modern age of growth and prosperity