Triassic Baikouquan Formation reservoirs in Wuerhe oilfield in Junggar Basin are of alluvial fan facies with low-porosity and low-permeability.No industrial oil flow can be tested without stimulation due to the low initial energy.Previous stimulation with water-based fracturing fluid failed

but stimulation with oil-based fracturing fluid in W36 well was successful.By using reservoir evaluation technique and experimental analysis techno-logy and referring to the standards of clastic reservoir evaluation

this paper thoroughly studied the sensitivity of sandy conglomerate reservoirs sensitivity within alluvial fan of Baikouquan Formation based on analysis of large amount of core flow test data.It is pointed out that understanding reservoir sensitivity and improving fracturing technique are quite important for prevention of formation damage and oil recovery.The study indicates that high content of clay minerals such as mixed illite/smectite and kaolinite is the main cause of strong sensitivity of the reservoir.Water sensitivity

salt sensitivity and volume flow rate sensitivity of the reservoir in Baikouquan Formation are moderate to strong(above average).Velocity sensitivity is a relatively weak.According to the results and production experiments

following measures

such as using dewatered oil-based fracturing fluid

controlling salinity of fracturing fluid(above 6 000 mg/L)and controlling flow velocity/volume flow rate

are proposed for preventing reservoir damage from sensitivity and increasing oil-gas production.