## 4 Results
### Pore Size Distribution  
The mercury injection curve from the HPMI experiments reflects the connectivity of pores and throats as well as their distribution characteristics. Owing to the selective distribution and skewness control of the reservoir pore-throat characteristics, the HPMI curves of turbidite and delta front tight reservoirs are classified into three types each. They correspond sequentially to six pore-throat combination types (Types A-F), with each curve shape representing distinct pore structure features (Figure 7). The displacement pressure distribution of turbidite reservoirs ranges from 0.676 MPa to 2.750 MPa. The maximum mercury injection saturation ranged from 71.790% to 81.980%. The distribution of the maximum pore-throat radius ranged from 0.267 to 1.087 um, with a mercury extraction efficiency ranging from 36.491-48.043%. Curve Types A and B represent slightly sorted coarse-skewed distributions, with a more pronounced platform period for turbidite reservoirs. Additionally, Type A exhibits coarser skewness than Type B does. However, Type C curves exhibit poor sorting and fine skewness, lacking a platform period, indicating a relatively poorer reservoir performance. The displacement pressure distribution of the sandstone in the delta front ranges from 2.045-8.260 MPa, with the maximum mercury saturation predominantly between 58.793% and 77.542%. The maximum pore-throat radius ranges from 0.089 to 0.359 um, with significant variations in each curve parameter and a mercury withdrawal efficiency of 27.168% to 50.725%. The Type D curve morphology represents poorly sorted and coarse-skewed pore structures, whereas the Type E curve signifies moderately sorted to moderately skewed structures. The Type F curve indicates poorly sorted and fine-skewed structures, with all three types lacking distinct plateau phases. Among these mercury injection capillary pressure curves, Type F has the highest minimum wet phase saturation value and a large volume of reservoir micropores but few macropores, indicating a relatively poor reservoir rock storage performance. Turbidite sandstone reservoirs mainly feature fine-medium pores (0.025-1 um), with a pore size distribution that is unimodal. The main peak almost exclusively corresponds to fine pores 0.025-0.1 um in size, with a main peak occurring in the 0.1-1 um medium pores. The cumulative pore volume of the turbidite sandstone samples ranged from 0.025 to 0.042 cm\({}^{3}\)/g, indicating significant changes in the cumulative pore volume in the Type B mercury injection curves. The delta front sandstone reservoirs have developed mainly micropores-fine pores (0-0.1 um). The pore size distribution exhibits both unimodal and bimodal characteristics, with significant variations in the main peak pore sizes. Micropores (0-0.025 um), fine pores (0.025-0.1 um), and medium pores (0.1-1 um) are present. The cumulative pore volume of the delta front reservoirs ranges from 0.009 to 0.026 cm\({}^{3}\)/g. Among them, the Type F mercury injection curves have the smallest cumulative pore volume, whereas the Type D curves have the largest cumulative pore volume. The Type E curves show significant variations in the cumulative pore volume, which are primarily distributed within the ranges of 0.010-0.015 cm\({}^{3}\)/g and 0.020-0.025 cm\({}^{3}\)/g. Additionally, both the Type D and F curves feature relatively developed medium pores. According to the analysis of the HPMI results, within the overall study area, turbidite sandstones exhibit smaller variations in curve parameters than delta front sandstones. Turbidite sandstone reservoirs demonstrate relatively better sorting, coarser skewness, lower minimum wet phase saturation values, smaller pore-throat volumes, lower displacement pressures, larger maximum pore-throat radii, and greater mercury withdrawal efficiencies. Therefore, rock reservoir properties are relatively superior to those of delta front sandstone reservoirs.