Research on production transformation technology for deep tight sandstone gas reservoirs in Xinjiang Oilfield
The deep unconventional tight sandstone reservoirs in Xinjiang Oilfield are characterized by deep burial,abnormal high pres-sure,high reservoir fracture pressure,high geothermal temperature,low porosity and permeability,strong heterogeneity,large lateral res-ervoir thickness changes,and multiple vertical distributions.The success rate of reservoir fracturing is low,and sand addition is difficult.The production and transformation process technology faces great challenges.In response to the difficulties in the transformation of tight sandstone reservoirs in this block,targeted transformation technogy for different reservoir types were optimized and formed:class Ⅰ res-ervoirs adopted the"barite removal+acidification"process to remove barite pollution and blockage,dissolve calcium in fractures,and dredge natural fracture systems;class Ⅱ and Ⅲ reservoirs with varying degrees of natural fracture development adopted fracture network fracturing technology.The pre fluid reduced the reservoir temperature and activated the natural fracture system,and the main fracturing fluid carried sand to form a high conductivity main fracture network system.For reservoirs with large thickness that cannot achieve uni-form vertical transformation through general transformation,a layered transformation process was adopted.For wells with interlayer stress differences of 2-5 MPa,the temporary plugging soft layering process was preferred,and the fracture network fracturing adopted a tem-porary plugging soft layering process with different particle size combinations of"powder+ceramist".For interlayer stress difference greater than 5 MPa,mechanical layering transformation process was adopted.If the span between two packers was greater than 60 m,me-chanical layering+soft layering composite layering process was adopted.A basic fracturing fluid system mainly composed of super guar gum thickener was developed,with ceramic particles with a particle size of 40-70 mesh selected as the proppants.The supporting tem-porary plugging and turning materials mainly include degradable fibers,fiber powders,and particle temporary plugging agents.The targe-ted reservoir transformation technology for deep tight sandstone gas reservoirs formed has important reference significance for exploring unconventional tight sandstone gas reservoir transformation technology.
deep tight sandstone gasstimulationmixed stimulationtemporary blocking diversion
万方数据
维普
