Carbonate formations associated with evaporite are important for the increase of global oil and gas reserves and production. Domestic and international exploration has confirmed that the discovery of many large-scale oil and gas fields is related to carbonate-evaporite assemblages
[1⇓⇓⇓⇓⇓-7]. In China, oil and gas discoveries in the Lower Paleozoic of the three major marine basins, namely Tarim, Ordos and Sichuan Basin, have confirmed that carbonate reservoirs are also associated with gypsum-salt rock
[8⇓-10]. Recently, exploration practice of the Cambrian subevaporite Xiaoerbulake Formation in the Tarim Basin and the fourth member of the Ordovician Majiagou Formation (Ma-4 in brief) in the Ordos Basin further proved the exploration potential of this assemblage
[11⇓⇓⇓-15]. At present, a large number of research results have been achieved by the predecessors in exploring the influence of evaporite on hydrocarbon accumulation in carbonates from the perspective of hydrocarbon generation, reservoir formation and hydrocarbon accumulation. On hydrocarbon generation, more attention has been paid to sediments and depositional environments. One viewpoint states that undercompensated basins, evaporative lagoons, platform-edge slopes and semi-occluded and occluded undercompensated bays are favorable environments for the high-abundance source rocks development
[16-17]. Another viewpoint believes that depositional environment plays an important role in the formation of marine hydrocarbon source rocks, and factors associated with biological productivity, depositional rate, and preservation conditions of the sedimentary environment can determine the type and abundance of organic matter in the hydrocarbon source rocks
[18-19]. Water stratification results in the enrichment of organic matter in the saline environment to form high-quality source rocks, and different types of source rocks are developed in different depositional environments with different depositional patterns
[20-21]. Some scholars have also focused on how gypsum-salt rocks affect the maturation of organic matter under overpressure and other environments, as well as the relationship between overpressure and hydrocarbon generation, which in turn affects hydrocarbon migration and accumulation
[22⇓-24]. In terms of reservoir formation, early studies focused on the influence of gypsum-salt rocks on dolomite diagenesis, and concluded that the influence of evaporite on dolomite reservoir formation is reflected in two aspects: (1) Mg
2+-rich reflux promotes the formation of intergranular pores by dolomitization; and (2) the dissolution of gypsum nodules forms gypsum- mold pores
[25⇓⇓⇓-29]. In terms of reservoir formation, the mainstream view is that gypsum-salt rocks mainly serve as a cap layer
[30]. Gypsum-salt rocks serving as a cap layer depends on their brittle and plastic properties which are controlled by temperature and pressure. Shallow buried gypsum-salt rocks are mainly brittle, and less effective for sealing hydrocarbon because they are easy to be destructed by fractures and faults
[31⇓-33]. Deep buried gypsum-salt rocks are plastic, and easy to flow and not easy to fracture, and even make the existing fractures and faults disappear
[34-35]. In addition, in recent years, some scholars have paid attention to the intrinsic connection of carbonate-evaporite combination from a comprehensive point of view, and have elaborated on the integrality and research connotation of dolomite-evaporite system (assemblage)
[36⇓⇓-39].