Study On Influencing Factors Of Acid-induced Fracture Conductivity Of Yingshan Formation Reservoir In ZG8-43 Well Area

There is also large proved reserve of oil and gas in Tarim Basin, Among them Tazhong NO:1 field ZG8-43 well area is an important area of increasing reserves and production, by the end of 2011, has accumulated proven geological reserves:gas 2524.48×108 m3, gas condensate 10976.27×104m3. This reservoir having a low permeability and low porosity characteristics, so that the fracturing is an important means to improve the production. Early in the fracturing process, since no clear understand of how the construction parameters and acid fracturing process influence the fracture morphology and conductivity, resulting in the construction is not ideal. To improve the effect of reconstruction, this paper carried out the acid etch and conductivity related simulations provide the basis for the acid fracturing construction area.Based on the extensive research of acid fructuring crafts and physical simulation, this paper established a experiment method to optimize the construction parameters and acid feucturing crafts, by using etching apparatus and conductivity test apparatus. This paper completed a different acid emissions, acid-rock reaction time, acid concentration influence of etching morphology and conductivity studies.The study found acid-rock reaction time control in less than 60 min, acid injection displacement at 400-500 mL/min can maximize fracture surface roughness, to obtain a higher conductivity. By simulating pad-acid-Fracturing and multi-stage acid frucruring, optimize the acid injection stages, and using a similar principle to the experimental parameters into the construction parameters to optimize ZG8-43 well area wells acid fracturing design to obtain a higher yield. Research shows that injection stage is different, the formation of cracks etched shape is different. At the optimum single-stage, pad fluid can form filter cake on the fracture suiface to slow down the acid-rock reaction rate the acid can not be effectively etched surface cracks, resulting in low conductivity.Two acid injection can improve the fracture surface roughness maximum extent possible, and to maintain a high flow capacity at each closure stress points. Three acid injection will crack surface anchor damage, high closure stress fracture easily closed. According to the optimize acid injection parameters and injection stages, it was found that 15min closed-acid fracturing can expand the channel. But long time cloesd-acid fructuring willAfter a single stage in accordance with the optimum acid injection parameters and optimum acid injection series of slab etched been closed acid fracturing experiments. The study found closed during acid fracturing acid preferentially into the cracks advantages flow channel, trench depth erosion, improve fracture conductivity, and long time can cause acid fracturing closing anchor corrosion, stress can not be closed in high effective support for cracks. Causing the anchor dissolution,can not crack under high closure stresses effective support.Engineering applications showe that the the experimental results have certain guiding significance...