Energy cooperation is an important part of building the Belt and Road,and Central Asia is the core area of oil and gas cooperation on the Belt and Road route.As one of the first enterprises to "go global",CNPC has made positive progress in oil and gas cooperation with Belt and Road countries.Exploring oil and gas cooperation in Central Asia in the new situation is of great practical significance for jointly building the Belt and Road,promoting regional cooperation and ensuring China's energy safety.

 

 

 

Over the past 80 years,dozens of underground coal gasification (UCG) mine field tests have been carried out around the world.However,in the early days,only a small number of shallow UCG projects in the former Soviet Union achieved commercialised production.In this century,a few pilot projects in Australia also achieved short-term small-scale commercialised production using modern UCG technology.However,the commercialisation of UCG,especially medium-deep UCG projects with good development prospects but difficult underground engineering conditions,has not progressed smoothly around the world.Considering investment economy,a single gasifier must realise a high daily output and accumulated output,as well as hold a long gasification tunnel to control a large number of coal resources.However,a long gasification tunnel can easily be affected by blockages and failure,for which the remedial solutions are difficult and expensive,which greatly restricts the investment economy.The design of the underground gasifier determines the success or failure of UCG projects,and it also requires the related petroleum engineering technology.Combining the advantages of the linear horizontal well (L-CRIP) and parallel horizontal well(P-CRIP),this paper proposes a new design scheme for an"inclined ladder"underground gasifier.That is to say,the combination of the main shaft of paired P-CRIP and multiple branch horizontal well gasification tunnels is adopted to realise the control of a large number of coal resources in a single gasifier.The completion of the main shaft by well cementation is beneficial for maintaining the integrity of the main shaft and the stability of the main structure.The branch horizontal well is used as the gasification tunnel,but the length and number of retracting injection points are limited,effectively reducing the probability of blockage or failure.The branch horizontal well spacing can be adjusted flexibly to avoid minor faults and large cracks,which is conducive to increasing the resource utilisation rate.In addition,for multi-layer thin coal seams or ultra-thick coal seams,a multi-layer gasifier sharing vertical well sections can be deployed,thereby saving investment on the vertical well sections.Through preliminary analysis,this gasifier design scheme can be realised in engineering,making it suitable for largescale deployment where it can increase the resource utilisation rate and ensure stable and controllable operations.The new gasifier has outstanding advantages in investment economy,and good prospects for application in the commercial UCG projects of medium-deep coal seams.

Since the Chinese economy entered the "new normal" stage,natural gas consumption in China has been sluggish and supply and demand have been relaxed.At the same time,environmental protection policies are intensified and the marketization process is accelerated.Many factors have intertwined with each other and affected Chinas natural gas consumption.Judging from Chinas economic growth,structural adjustment of and energy consumption,and the scale and structure of global natural gas utilization,we believe that there is still significant rise of natural gas consumption in China.However,there are still many problems that hinders the utilization of natural gas,which may be solved by policies and market-oriented reforms.Taking natural gas-based distributed energy as an example,this paper analyzes the change and influence of relevant policies,and puts forward proposed incentive policies to promote the utilization of natural gas in China under the economic "new normal".