Research on Formation Mechanisms of Hot Dry Rock Resources in China

As an important geothermal resource, hot dry rock （HDR） reserves have been studied in many countries. HDR resources in China have huge capacity and have become one of the most important resources for the potential replacement of fossil fuels. However, HDR resources are difficult to develop and utilise. Technologies for use with HDR, such as high-temperature drilling, reservoir characterisation, reservoir fracturing, microseismic monitoring and high-temperature power stations, originate from the field of oil and drilling. Addressing how to take advantage of these developed technologies is a key factor in the development of HDR reserves. Based on the thermal crustal structure in China, HDR resources can be divided into four types： high radioactive heat production, sedimentary basin, modern volcano and the inner-plate active tectonic belt. The prospective regions of HDR resources are located in South Tibet, West Yunnan, the southeast coast of China, Bohai Rim, Songliao Basin and Guanzhong Basin. The related essential technologies are relatively mature, and the prospect of HDR power generation is promising. Therefore, analysing the formation mechanisms of HDR resources and promoting the transformation of technological achievements, large-scale development and the utilisation of HDR resources can be achieved in China.

A worthy technique for transcanal drilling during endoscopic ear surgery

Objective:To evaluate the necessity and effectiveness of a preplanned technique for drilling during transcanal endoscopic ear surgery.Methods:Study design:Retrospective case series study from June 2011 to June 2015.Setting:Private tertiary care hospital.Patients:Eighty-five ears of 78 patients,age ranging from 9 to 57 years underwent transcanal endoscopic drilling for various types of pathology in their middle and external ear.Interventions:Application of a preplanned technique for transcanal drilling in endoscopic ear surgery that involved short timed drilling with use of intermittent irrigation and suction.Every events of the procedure were done one after another with the single hand of the surgeon.An attachment providing protecting sheath around rotating burr was used during each time of drilling.Main outcomes measure:Efficacy of such drilling technique in single handed endoscopic ear surgery.Presence of any postoperative thermal injury of facial nerve and any lacerated injury of skin of external ear.Results:This preplanned technique was found suitable for transcanal endoscopic drilling with the single hand of the surgeon.Postoperative facial nerve palsy or laceration of skin of external ear was not noted in any patient.Conclusion:After using the present technique,transcanal endoscopic drilling could be done easily and safely with single hand of the surgeon.

Repacking practice for G-3 engineering driller power unit with drive shaft of dual channel reverse circulation

In order to satisfy operating requirements for constant core drilling technology in reverse circulation with hollow-through DTH,the power unit of G-3 engineering driller was ameliorated. The new one with dual channel drive shaft, achieved the perfect assemble with transmission structure of the original power unit. It could interconvert according to need by using two sets of drive shafts with direct and reverse circulation. The repacked G-3 engineering driller carried on experiment in the field test in Luanchuan molybdenum mine of Henan, whose effect was very good.