Dynamic And Quantitative Prediction Model Of Thermal Evolution Of Organic Acids In Formation Water And Its Application Research In Northern Songliao Basin

The reservoir property determined the extent of oil-gas accumulation. The porosity which was one of the most important parameters of reservoir property was affected by the feldspar dissolution or precipitation of organic acids. The main source of organic acids was thermal degradation reaction of kerogen. The distribution of organic acids in reservoir had characteristics of increased firstly and decreased finally because of thermal evolution.Currently, the cognition of organic acids distribution in many regions was obtained by the summary of oilfield water data from basin and region which was discovered. The reliable quantitative prediction technology of evolution and distribution of organic acids was not established in the areas which was low extent of exploration. It restricted seriously prediction or assessment of reservoir. And it can also limit the application research of evolution and distribution organic acids about oil-gas exploration.Based on summarizing the characteristics of experimental data of organic acids hydrous pyrolysis, the relation between the reaction conditions and dynamics behavior of organic acids pyrolysis was analyzed. The single molecule decarboxylation reaction was the main pathways which organic acids was decomposed under the geological condition.Combined with the programmed temperature or production characteristics of experimental process, the scientific processing method which required the experimental data was established. It also set up the single factor optimizing calibration method which can calibrate kinetics parameters. The calibration results of activation energy and pre-exponential factor of organic acids decarboxylation reaction is 182.46kJ·mol-1 and3.10×109s-1. The dynamic and quantitative prediction model of thermal evolution of organic acids in formation water was established. The organic acids thermal evolution history of Quan4 Formation was predicted by using model and burial history or thermal history of Quan4 Formation of Northern Songliao Basin. It was completely consistent with the current distribution features of measured organic acids in formation water. It can show that the model could predict dynamic and quantitative thermal evolution of organic acid in formation water. The research of dynamic and quantitative prediction of organic acids in formation water shows that decarboxylation extent of organic acids in Depression Qijia ishighest, and Daqing Placanticline is followed. Depression Sanzhao is the lowest. The thermal evolution extent had the increasing trend from east to west direction.In addition, the model can be used for the various studies of petroleum geochemical.For example, it can calculate the potential and conversion amount of organic acids of different reservoirs. The actual calculation shows that the characteristics of potential amount of organic acids of four reservoirs is: Fuyu>Saertu ≈Putaohua>Gaotaizi. The conversion amount of organic acids is: Fuyu>Gaotaizi>Putaohua>Saertu. The linear relation of organic acids conversion amount and porosity was established to predict the distribution of porosity. The model can also be used to calculate the contribution of methane pyrolyzed by organic acids to gas reservoir.