The Laboratory Study Of Rock Permeability Under Formation Conditions In Changqing Upper Paleozoic Reservoir

By use of the data of thin section and core, the paper is focus on the use of experimental analyse to study the reservoir's permeability under ambient conditions (plug and whole core samples), confining pressure and formation conditions, and analyzes the influence that pressure and temperature have on permeability. Simulate different producting pressure drop and based on the permeabilities' changing law, linking the theory of gas field development and the field reality, stating from the reservoir protection, the paper gives reasonable producting pressure drop and per-well production. Finally, the paper evaluates comprehensively the reservoir by summing up the petrology features, physical properties, pore structure and performance data. The results indicate that:1) The Changqing upper Paleozoic reservoir is tight reservoir with low porosity and low permeability.2) Confining pressure increased, rock permeability is lowering. The more low, and the influence is the more greatly.3) The permeability with high temperature is obviously lower than that with normal temperature under the same confining pressure condition. The decrease temperature makes is increasing as the permeability lowered.4) Permeability by simulating different producting pressure drop is more lower than the one with no irreducible water under high pressure and high temperature.According to the results of different simulating pressure drop in the course of simulating production and combining with the reservoir, the paper puts forward some proposals from reservoir protection and permeability sensitivity angle.1) The critical producting pressure drop of type I reservoir should be under IMPa. The type II and III reservoir should be controlled within 4MPa, and 11 MPa is suitable to the type IV.2) Strengthen the study of reservoir sensitivity, especially the process measure in the course of well drilling and completion, the study of prescription of drilling and completion fluid, to avoid and lighten particle encroaching and water lock effect..3) Carry out large hydraulic fracturing to establish created fracture which is the favorable way. Pay attention to the water lock effect and use nonpenetrating-type fluid to decrease the encroaching depth.