MicroTransporting Capability of Sandstones in the Shallower Strata of Dongpu Sag and Its Significance

Key words: 
• microtransporting capability /
• pore structure /
• poretothroat ratio /
• shallower strata /
• Dongpu sag

Abstract: There has no the ability of generating oil and gas in the shallower strata of Dongpu sag. Developed as one of the most important transporting body, the sandstone connects deeper hydrocarbon source rocks and shallower trap, so sandstone transporting capability directly determines if or not the hydrocarbon accumulation can happen in the shallower strata. The evaluation of sandstone transporting capability is one of weak links in the study of transporting body; the micro transporting characteristics determine quality of sandstone transporting capability. Since there has defects in microscopic property measurement techniques of conventional sandstone, this article by means of the measuring software on pore diameter named Scandium in scanning electron microscope for the first time, the sizes of pore and throat of shallower strata in Dongpu sag are distinctively measured systematically in microscopic scaling. Then the longitudinal distributing characteristics are summarized. The transporting capability of the sandstone and its change are analyzed. All of these offer a new method in the study of pore structure and sandstone transporting capability. It shows those throat width and poretothroat ratios are the main factors influencing the transporting capability of shallower strata. The sequence of sandstone transporting capability more and more better are the first segment of Shahejie Fm.(Es1), to Dongying Fm.(Ed) and Guantao Fm.(Ng). However, the transporting capability in Minghuazhen Fm.(Nm) upon Guantao Fm.(Ng) is worse again; Hereby, if the others conditions of migration and accumulation are satisfied, hydrocarbon may migrate to the Guantao Formation and accumulate here. 