Recognition of the Types of Buried Hill Gas Reservoirs in Yangshuiwu and Its Significance

Yangshuiwu buried-hill gas reservoir is a Paleozoic carbonate gas reservoir recently discovered in Huabei Oilfield. However, due to the unclear understanding of the gas reservoir, some Wells failed to select the main strata and failed. It is urgent to re-understand the gas reservoir types in order to realize the efficient development of gas reservoir. Therefore, through the analysis of oil, gas and water, formation pressure coefficient and reservoir characteristics in this area, it is found that the properties of produced water in production Wells are very different from edge and bottom water, and there is no edge and bottom water in the production area. The properties of natural gas and condensate oil and the formation pressure coefficient are different in the longitudinal direction. The reservoirs are mainly distributed in the upper part of Fengfeng Formation, the top part of Shangmajiagou Formation and the middle and upper part of Liangjiashan Formation, with layered distribution. The interlayers between the reservoirs are composed of high resistance limestone and high GR marl. The analysis of gas reservoir model shows that the Yangshuiwu Buried hill gas reservoir is layered gas reservoir, in which the Liangjiashan Formation is fractured and porous reservoir with thick and concentrated development, which is the main target of Yangshuiwu buried-hill. Local traps can be formed in the south of the Hexiwu buried hill, which is a favorable target area for searching for buried hill oil and gas reservoirs.