## 4 Experimental Results and Discussion
### Comparison of Production Characteristics and Analysis of Porous Flow Mechanism  
(1) Comparative characteristics of conventional CSS and E-CSS  
Figure 8 shows the comparison of the oil production rate for conventional CSS and E-CSS. From Figure 8, the comparison of oil production speeds shows that conventional CSS had a rapid decline in production during the production phase, while the use of electric heating effectively slowed down the decline in production. The statistics of four cycles of conventional CSS were 281 mL, 237 mL, 118 mL, 113 mL, and the total oil production was 749 mL; that of E-CSS was 460 mL, 253 mL, 280 mL, and 197 mL, a total of 1290 mL. The average cycle oil increase was more than 50% and the enhanced oil recovery effect was obvious. During the experiment, there were certain fluctuations for production of heavy oil, and there were also certain fluctuations in the corresponding oil increase, but the overall oil increase was obvious. (2) The influence mechanism of electric heating on the decline rate. For each CSS round, the effect of the heat injection on the instantaneous output at different production times in the CSS cycle can be expressed by the following formula:  
\[\frac{1}{q_{o}(t)}=\frac{\eta\rho_{o}C_{o}(T_{s}-T_{R})s}{Q}t_{4}+\frac{1}{q_{ \rm oil}} \tag{13}\]  
Figure 7: The comparison of the temperature field at the end of the second cycle production phase. \(\frac{\eta\rho_{o}C_{o}(T_{s}-T_{R})s}{Q(t)}\) is the slope of the relationship curve of \(\frac{1}{q_{o}(t)}\) and \(t_{4}\), which is the limit on the rate of yield decline. For conventional CSS, the heat injected into the oil layer \(Q\) is the enthalpy \(Q_{s}\) of the injected steam. For E-CSS, the heat injected into the oil layer \(Q\) is the enthalpy \(Q_{s}\) of the injected steam and the enthalpy \(Q_{e}(t_{4})\) of the electric heating input. To sum up, the decreasing rate of conventional CSS is \(\frac{\eta\rho_{o}C_{o}(T_{s}-T_{R})s}{Q_{s}}\), and the decrement rate of E-CSS is \(\frac{\eta\rho_{o}C_{o}(T_{s}-T_{R})s}{Q_{s}+Q_{e}(t_{4})}\). Since \(Q_{e}(t_{4})\) increases with time, the slope value decreases with other parameters unchanged, so the decline rate of output decreases with time. The enthalpy of steam injected into the first 1, 2, 3, 4 CSS cycles was 952,700 J, and the enthalpy of the electric heating input oil layer was 1,277,075 J, 2,899,011 J, 2,980,319 J, 2,980,250 J, respectively. Based on the calculation, the decline rate of E-CSS of the 1,2,3,4 only accounts for 42.7%, 24.7%, 24.2% and 24.2% of conventional E-CSS. (3) The effect of electric heating on the porous flow resistance to the well. In the process of CSS in the horizontal well, the porous flow resistance of the fluid at any point in the horizontal section \(R\) is equal to the sum of the horizontal porous flow resistance \(R_{h}\), and the vertical porous flow resistance \(R_{v}\):  
\[R=R_{h}+R_{v}=\frac{\mu_{o}(T)B_{o}}{2\pi Kh}\left(ln\frac{a+\sqrt{a^{2}-\frac {L^{2}}{4}}}{\frac{L}{2}}+\frac{h}{L}ln\frac{h}{2\pi r_{w}}\right) \tag{14}\]  
Since the viscosity of crude oil is a function of temperature [22],  
\[\text{Log}(\text{Log}(\mu_{o}(T)+0.8))=\text{A}+\text{BLog}(T+273.15) \tag{15}\]  
where A and B are factorless coefficients, and it is a contant value for the specific crude oil, the results of the viscosity-temperature experimental test are regressed. In this article, A of heavy oil in the target area is 9.26, and B is \(-3.44\). Substitute the values of A and B into the Formula (15) and get it by transformation:  
\[\mu_{o}(T)=10^{10^{9.26-3.44\text{BLog}(T+273.15)}}-0.8 \tag{16}\]  
Replace Formula (16) into (14) to obtain the flow resistance \(R\) of conventional CSS and the flow resistance \(R_{e}\) of E-CSS. Figure 8: Comparison of oil production rate for conventional CSS and E-CSS.