柴达木盆地北缘昆2井第三系深部储层岩性由成分成熟度和结构成熟度均较低的岩屑砂岩或长石岩屑砂岩组成，而杂基含量较高（一般大于15％）是造成该储层物性先天较差的主要原因。昆2井经历的成岩作用有压实作用、胶结作用、交代作用和微弱的溶蚀作用，其中，碱性成岩作用控制了储层成岩演化特征，压实作用和不同期次碳酸盐胶结作用是造成储层物性变差的主要成岩改造原因。深部储层N ₁、E₃和E ₁₊₂主要处于早成岩阶段B期的晚期和晚成岩阶段的A期和B期，其中上干柴沟组（N₁）储层为低孔—低渗储层夹特低孔—特低渗储层，孔隙度在0.1%～15.59%之间，平均为7.75%,渗透率在 （0.1～37.38）×10^-3μm ²之间,平均为13.23×10^-3μm ²，储集空间以粒间贴边孔为主，适于储集天然气，但也可储集少量石油；下干柴沟组(E₃) 储层为特低孔—特低渗型储层,孔隙度在2.2%~14.3%之间,平均为5.0%,渗透率在（0.02~5.55）×10 ^-3μm²之间,平均为0.58×10^-3μm²，储集空间以裂缝孔为主，适于储集气态烃。

The deeply-buried Tertiary clastic reservoirs of the Well Kun 2 in the Qaidam basin are mainly composed of lithic sandstones and feldspathic lithic sandstones with lower compositional and textural maturation degrees. The much higher content of matrix (generally >15%) is the dominant cause for porosity damage during sedimentation of these clastic reservoirs. The reservoirs in Well Kun 2 have undergone the mechanical compaction, cementation, replacement, and weak dissolution, of which the compaction and carbonate cementation with different phases are the two main factors responsible for porosity reduction during the increasingly progressive diagenesis. The deeply\|buried reservoirs (including N₁, E₃ and E₁₊₂) are now in late B period of early diagenetic stage, and periods A and B of late diagenetic stage. The diagenesis occurred in the alkline diagenetic environment controls the diagenetic evolutionary features of deeply\|buried clastic reservoirs in Well Kun 2. The clastic reservoirs distributed in Upper Ganchagou Fm.(N₁) are mainly low porosity-low permeability sandstones containing a few extremely low porosity and permeability reservoirs, with porosity ranging from 0.1 to 15.59%, averaging 7.75%, and permeability from 0.1 to 37.38×10^-3μm², averaging 13.23×10^-3μm². The reservoir spaces of the clastic reservoirs are mainly compressed intergranular pores which are favorable for preserving natural gas, but could also contain a few crude oil. The reservoirs of Lower Ganchaigou Fm.(E₃ ) are mainly extremely lower porosity and permeability clastic sandstones, with porosity varing from 2.2%~14.3%, averaging 5.0%, permeability from 0.02 to 5.55×10^-3μm², averaging 0.58×10^-3μm², which can act as gaseous hydrocarbon reservoirs with dominant spaces composed of fracture pores.