By investigating the application effect and practical experience of CO2 huff and puff projects，we analyzed the reservoir characteristics suitable for CO2 huff and puff from nine parameters in four categories，namely geological features，reservoir characteristics，fluid properties，and development characteristics. According to the laboratory experiments，the expansion coefficient of crude oil in the CO2-injected formation in Block JL exhibits such an evident increase and the elastic energy of the formation could be well supplemented，which means the formation is the suitable for CO2 huff and puff. Meanwhile，the surfactant CRS-1080 can effectively reduce the interfacial tension between fluids and increase CO2 swept volume，thus improving the effect of CO2 huff and puff. Combined with well selection conditions and laboratory experiments，Well X1 in Block JL was selected to carry out the pilot test of CO2-chemical composite huff and puff，after which the reservoir energy was effectively supplemented and the production decline trend of near wells was restrained. The test showed that this technology has certain applicability to this block.