Papers by Author: Xu Zhang

Abstract: The Proved, Probable and Possible Reserves of a gas reservoir in Sichuan Basin is more than 400 billion cubic meter. It has very good prospects for development. In this paper, a preliminary discussion was taken on countermeasures of gas reservoir basing on analysis of the main geological properties and challenges of the development of the gas reservoir. This study proposed to strengthen the comprehensive geological study of the gas reservoir and resource base to increase the single well productivity and decrease the cost. The existing achievements must be combined with self-dependent innovation to form the right technologies of development quickly by investigation study and pilot test to help the gas reservoir develop fast, efficiently and safely.

Abstract: Due to a small amount of test and dynamic data in the early development, it is unable to quickly and accurately predict the reservoir capacity. In this paper, we use the logging data of a block of sand four in Song Liao Basin to identify the evaluation methods that the key factors affecting the reservoir capacity. On this basis, the establishment of a relational model of reservoir oil permeability and productivity indices for predicting the reservoir capacity rapidly in early development. It has higher forecast accuracy by comparison with the measured values.

Abstract: The transport of pathogenic bacteria from wastewater treatment facilities in subsurface has attracted extensive concerns over recent decades, while the impact of effluent water chemistry remains unclear. The influence of retention time in effluent from a municipal wastewater treatment plant on bacterial surface properties and deposition of Escherichia coli strains in saturated quartz sand packed-bed columns was investigated in this paper. Retentions in effluent significantly altered bacterial surface properties, such as zeta potential, surface charge and hydrophobicity, subsequently changed their deposition rate coefficients and attachment efficiencies in quartz sand packed-bed columns. Under low ionic strength conditions, bacterial deposition onto quartz sand grains was in agreement with the predictions of DLVO theory, in which the secondary energy minimum was demonstrated to be predominant.

Abstract: A prototype three-dimensional tool oscillation system for finishing metal molds, which can oscillate a tool in a figure-8 motion, has been developed. When such a tool motion is used, the lapping direction alternatively changes and consequently a very smooth surface might be achieved in a relatively short time in the presence of a very fine abrasive compound. The developed tool oscillation system consists of three multilayer piezoelectric transducers. The orientation of the tool motion can be changed in three dimensional space. This paper describes the structure of the tool oscillation system, the driving method of the three piezoelectric transducers for oscillating a tool in a figure-8 motion and the measurement results for the tool motions.