Research On Mechanism And Operating Technology Optimization Of In-situ Gas Generating In Reservoir

In this paper, the mechanism and operating technology of in-situ gas generating were studied in order to enhance oil recovery and enlarge applications scale. The research involves: reaction rules of gas generating agents in porous media, injecting parameter optimization and displacement mechanism.The main conclusions in this research is: 1) In reservoir with higher original temperature, pressure and temperature increased fast and can reach higher peak value after gas generating agents injecting. In reservoir with higher original pressure, pressure increased fast and can reach higher peak value after gas generating agents injecting. Original reservoir pressure had less effecting on heating rate and peak value of temperature. 2) The mechanism of in-situ gas generating to enhance oil recovery involves: displacement effect, lower W/O interfacial tension, expansion effect, change microscopic oil- water distribution. The gas generating effect devote more oil recovery than heat generating effect, about 3-4 times. 3) The pressure difference between inlet and outlet of core can be decreased 10% when plug removal by gas generating agents only. The pressure difference can be decreased 21% when plug removal by gas generating agents and mud acid. The pressure difference can be decreased 28% when plug removal by gas generating agents and fluoboric acid. 4) When gas generating and foaming agents were injected, reservoir permeability can be adjusted due to jamin effect. 5) Operating technology parameters was optimized by experiment: surfactant injecting volume is 0.2PV, gas generating agents injecting volume is 0.3PV, Stuffy well time is 16 hr. 6) O il recovery of huff and puff by gas generating agents preposition foam is 12.5%. O il recovery of huff and puff by gas generating agents preposition gel is 17.7%. O il recovery of huff and puff by surfactant preposition gel is 15.5%. Preposition gel can plugging high permeation layers, thus swept volume were enlarged. O il recovery of huff and puff by gas generating compound agents was promoted 8.7% than single agents.