Shale gas as an important unconventional resource，is essential for our energy security and supply，but the shale reservoir is of low porosity and extra-low permeability characteristics，and hydraulic fracturing is needed to obtain the desired economic output. We summarized the advanced technology used in American shale gas exploitation in the paper. Based on the shale gas reservoir characteristics and technology development of China，we also discussed the directions of large-scale development of shale gas in China. The results indicate that economical development of north American shale gas benefited from the advanced reservoir evaluation，horizontal drilling and hydraulic fracturing. And we also further evaluated the latest developments in north American shale gas，including reservoir evaluation，fracturing material and design optimization，production evaluation. In addition，discussion of technology adaptability and basic principles of various technologies are presented. In order to improve the development of shale gas in China，from exploration to development，we should learn from combining advanced experience with our reservoir features to carry out science and technology research，such as whole optimization of exploration and development，the volume fracturing mechanism and related technology，the evaluation of negative effects of shale gas development.
The mainly difficult problem of production inadequate return top of slurry and poor bonding cementing hole reaction are discussed in the paper; the effective factors of cementing quality – poor slurry property, lost circulation, poor displacement in long bare hole, and o8il-gas-water migration in the processes of slurry setting are analyzed; the technical countermeasure of enhancing cementing quality and preventing casing corrosive are presented. The previous troubles are solved satisfactorily and marked economic benefit abstained by using these techniques in low temperature, weak and oil-gas-water active formation.
In the high CO2 oil and gas field operations，the applicability of rubber O-ring has a certain effect on the production safety. Previous studies related to the rubber O-ring is merely in a free state，but in the actual operating condition，the rubber O-ring is mostly in a compressive stress state. Therefore，we designed a new device for corrosion resistance and sealing property test of rubber seals in a compressive stress state，in the harsh environment with pressure of 35 MPa，temperature of 140 ℃，gas phase composition of 5%CO2 and 95%N2，and the CO2 corrosion resistance experiments on the O-rings of four kinds of rubber materials were conducted. Through comparing the mechanical properties and morphology changes before and after corrosion， the applicability evaluation of them in the above experiment environments was made. The study found that the mechanical properties of O-rings after corrosion decreased. The corrosion extent of O-rings was weaker in the compressive stress state than in the free state，and in the compressive stress state，the liquid corrosion was weaker than the gaseous corrosion，but stronger in the free state. After corrosion the swelling and aging of O-rings occurred，which caused the seal failure. The study provided references for the selection and use of rubber seals in the high temperature and high pressure oil and gas field with high CO2 content.
Control of drill string vibration and shockis an important basis for track optimizing，wellbore design and precise control，optimization of drilling parameters，improving drilling speed and intelligent drilling. In deep water，ultra-deep water， deep well，ultra deep well，hard and brittle shale gas formations and gas drilling operations，cluster wells，directional wells and other special drilling technologies are employed，but these complex wells increases losses by vibration and shock. We systematically explained and compared the forms and methods of performance evaluation of the drill string vibration and shock and divided the drill string vibration and shock into passive control，active control and semi-active control. Based on a summarization and recent classification of critical control methods and the structure and principle of critical controlling equipments， we focused on the representative achievements and made a comparative analysis of the corresponding methodological characteristics， equipments and application range，which resulted in the procedures of drill string vibration and shock control and revealed the direction of future research.
Based on the basic physics principle，this paper presents a mechanism model for multiphase flow in gas wells using foam dewatering technology，which can be applied to various flow patterns. Firstly，based on the experiments of Mitchell and Taitel，the model considers four distinct flow patterns（bubble，slug，homogenous foam，and mist）and formulates the transition boundaries among them. Then individual models for four flow patterns are developed. Bubble flow and slug flow are described by the drift flow models. Homogenous foam flow is treated as power-law fluid. Mist flow is simplified as no-slip model. The evaluation results using pressure test data in 39 foam lift gas wells indicate that the unified model shows an average error of -0.55%. Sensitivity study shows that foam lift gas well may experience bubble flow or slug flow while the gas-liquid ratio is low. Appropriately supplying gas can move the flow into the homogenous foam flow，which can improve the lifting efficiency.
A polymer of octadecyl acrylate has been synthesized in solution and the effect of initiator, monomer, temperature and solvent on the polymerization reaction rate has been studied. Results have shown that the reaction rate is in direct proportion to the first power of monomer concentration and a half power of initiator concentration. Polymerization reaction constant factor Aais 123.4, the activity energyEais 29.72 KJ/mol. The type of solvent has little influence on the polymerization rate and there is no accelerating polymerization. The order of chain transfer constant of four solvents is:CCl4>CHCl3>(CHCl2)2>C6H5CH3.
Hydrogenation cracking tail oil is of excellent performance, with high saturated hydrocarbon content, low sulfer and nitrogen content, it can be ethane cracking substance, also good quality basic oil raw material of lubricating oil, it can also be used to produce transformer oil, combustion engine oil and hydraulic oil etc., meanwhile, the by product of diesel can be obtained. Hydrogenation cracking tail oil from Liaoyang petrochemical Corp. is researched in Lab, the utilization of the hydrogenation cracking tail oil as basic oil of lubricating oil is investigated through the technique of vacuum distillation, solvent dewax and replenishment refinement. Research indicates that 15.3% HVI100 basic oil recovery, 35.4% HVI150 basic oil, 20.4% HVI 400 basic oil, diesel and transformer oil, can be obtained through hydrogenation cracking tail oil.
