The deep reservoirs are mainly referred to as the 5th sand layer in the lower part of the 3rd member of Hetaoyuan Formation and Dacangfang Formation in Biyang sag

they are characterized by their low porosity and low permeability.These oil/gas reservoirs have been damaged heavily in the course of drilling

well completion

perforation and testing.As a result

the oil/gas reservoirs would often be difficult to be found

and the productivity of those reservoirs with low porosity and permeability would be relatively low.Well productivity can only be increased by stimulation treatment.Through various studies

reservoir protection and stimulation techniques

such as formula of high quality drilling fluid

temporary plugging method and advanced reservoir protection technique with polymeric alcohol

high quality perforation fluid and underbalanced perforation

have been applied

and significant results have been obtained in Zhaowa-Anpeng area.As for stimulation

optmimization of high quality fracturing fluid has also been made

which are characterized by its heat-resisting quality

good compatibility

low friction resistance

and high proppant-carrying capacity.Besides

application and dissemination of large-scale fracturing technology have also been made in Zhaowa-Anpeng area

which prove to be highly effective.