Experimental research on the performances of water jet devices and proposing the parameters of borehole hydraulic mining for oil shale.

Jiwei Wen,Urso Campos,Chen Chen,Xiao-Jun Yang

doi:10.1371/journal.pone.0199027

Abstract

Oil shale is an unconventional energy source, and it is also a potential petroleum substitute. Nowadays, the energy shortage is becoming more and more prominent, oil shale has attracted the attention of energy researchers all over the world. Borehole hydraulic mining is an effective method to exploit the underground oil shale which has more prominent advantages than other conventional mining methods. Jet devices are the key component of borehole hydraulic mining, which include the straight cone nozzle, organ pipe nozzle and self-excited oscillation pulsed jet nozzle. Also, the reasonable mining parameters are also crucial in mining underground oil shale efficiency. The jet characteristics of the non-submerged water jet, submerged water jet, direct water jet, cavitating water jet, and pulsed water jet are also explained and compared based on theoretical analysis. The jet performance of the non-submerged water jet is better than the submerged water jet. Each type of jet devices has its own basic principles and optimal structural parameters. The best operating scheme of borehole hydraulic mining for underground oil shale is to use the pulsed water jet which is produced by the self-excited oscillation pulsed jet nozzle to break underground oil shale under the non-submerged condition. Moreover, the pulsed water jet should be placed parallel to the oil shale bedding. In addition, under the preconditions of ensuring the safety and reliability of the hydraulic mining equipment and pipelines connection, the jet pressure and jet flow should be raised as much as possible, so as to obtain the much higher mining efficiency. These results and conclusions can provide very valuable guidance for borehole hydraulic mining of underground oil shale.

Highlights

There is no doubt that energy has always been one of the substances closely bound up with human daily life
The most significant advantage is that the method does not need to remove the overlying strata
In the beginning of 20th century, the United States carried out the research on borehole hydraulic mining technology, and successfully carried out the mining of uranium deposits, asphaltene sand, granular phosphorite and sandstone, which was subsequently applied in production practice in Russia, Yugoslavia, and other countries [11,12,13,14,15,16]

Summary

Introduction

There is no doubt that energy has always been one of the substances closely bound up with human daily life. Among these four mining methods, borehole hydraulic mining technology is the especially suitable for mining deep and low-grade underground oil shale deposits [9,10,11,12,13,14,15] It follows the same basic principles as the high-pressure jet grouting and hydraulic coal mining, they all use high-pressure jet to break the ore bed or the rock and soil mass [14,15,16,17]. The most significant advantage is that the method does not need to remove the overlying strata It will bring the obvious benefit is a simple, reliable, and safe operation. Bondarchuk presented the technological processes of borehole hydraulic mining for pay zone development [17]

Objectives

Discussion

Conclusion