Fractured Carbonate Reservoir Failure Development Mechanism Of Experimental Research

Based on core and geological data in Changing gas field , by the technique of experimental analysis and combined with the theory of rock pore compressing, some research experiments of the cores of this area are designed as follows: the research experiment of core porosity under the condition that normal pressure and normal temperature; the research experiment of core porosity sensibility to stress path under the condition that simulate formation; the research experiment of core permeability under the condition that normal pressure and normal temperature; the research experiment of core permeability sensibility to stress path under the condition that high pressure and high temperature; the research experiment of core permeability sensibility to stess path under the condition that simulate formation; the research experiment of simulating depleting exploitation under the condition that simulate formation. Finaliy , the reservoir sensibility to stress path are evaluated by combining the research results as above mentioned with the petrology features ,the physical properties, and the pore structure of this area . The results are indicated:1. Based on the analysis of field core, knowing: The Tarim under Ordovician reservoir is carbonate reservoir with tight basis and highly heterogeneous and comprehensive void for penetrating and contain.2. Successfully made the map cracking,which not only conform to the lungu reservoir,but also deliver the goods of liquid permeability,possess pipe flow character.All above make core laboratory sample simultaneously achieve the standard at pore and permeability.3.The experiment research of core porosity sensibility to stress path under the condition that simulate formation indicates that the rock porosity is reducing with the overlay pressure increasing.The amplitude of porosity reducing is relation with rock' pore stucure.4.Under the higher pressure and higher temperature, the permeability is reducing with the overburden pressure increasing. The amplitude of reducing permeability is relation with rock' pore stucure.5. After the porosity sensibility , permeability sensibility, temperature sensibilitytest .The sensibility model to stress path of map cracking carbonate formation reservoir is set up, comprehensively the reservoir formation sensibility to stress path is evaluated in this area.6. Under high pressure, high temperature and high salinity,Succeessfully finished the depletion test using map cracking core,know that the displacement efficiency of high permeability core is well above that of middling permeability core's; displacement efficiency increase with the incresment,the character of fluid and cores greatly affect the displacement efficiency; the displacement efficiency increase with the displacement velocity; the difference in pressure, the quantity of oil and gas, gas oil ratio alternately change with displacement, wo can see: naphtha oil have oil sect dam and gas sect dam; oil and free gas unequably distribute,whichgreatly different with sand stone core.7. The displacement efficiency under the static overburden pressure is better than that of under static effective pressure beyond a certain depleteion pressure range,but the variation tendency of forward two means are the same.static pressure displacement must be controlled to a certain pressure,But the static effective pressure displacement fit for all pressure,for under the static overburden pressure , rock matrix may be plastic deformation disrupt even rock mass broken up.which may leads to unrecoverable disrupt of the permeability and porosity performance. Which indicate that wo need pressure maintaining when reach a certain pressure.