A method for adjusting steam injection mode in the process of steam huff and puff
An adjustment method and steam injection technology, which is applied in earthwork drilling, wellbore/well components, production fluid, etc., can solve problems such as uneven steam absorption, less oil production in low-permeability areas, and poor recovery effect of heavy oil, achieving Improve the degree of production, increase the oil-steam ratio, and improve the effect of uneven steam absorption
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0054] A method for adjusting the steam injection mode in the process of steam huff and puff,
[0055] 1) Heterogeneous reservoirs have serious uneven steam absorption and high oil saturation in horizontal well sections. (Oil saturation range R=So max -So min , where So max is the regional maximum oil saturation, So min is the regional minimum oil saturation. ) If the coefficient of variation of formation permeability is 0.27, the horizontal well injects steam for 290 m 3 / d, under the conditions of temperature 250℃, steam dryness 0.7, such as figure 1 After the end of the third cycle, the temperature in the low-permeability zone at the front end of the horizontal well was lower, and the temperature in the high-permeability zone at the rear end was higher, and the temperature had already shown obvious characteristics of low front and high temperature. The phenomenon of uneven steam absorption in the horizontal well section of the cycle is more obvious, and the steam abso...
Embodiment 2
[0068] The degree of heterogeneity of the ground layer increases, V k =0.74, horizontal well steam injection 290m 3 / d, under the conditions of temperature 250℃ and steam dryness 0.7, the temperature variation coefficient is higher than that of the previous case, but the overall change has the same trend. After the steam huff and puff starts, the temperature variation coefficient increases rapidly. The oil in the reservoir is produced in large quantities, the water saturation gradually increases, and the effect of the back-end steam to heat the formation becomes smaller. As the front-end temperature increases, the temperature variation coefficient gradually decreases. like Figure 11 , the steam huff and puff starts to decrease in the second cycle, and after two consecutive cycles, the temperature variation coefficient reaches a minimum value in the fourth cycle. The fourth cycle temperature coefficient of variation is 11.96 and the fifth cycle is 12.
[0069] The best ad...
example
[0073] Oilfield 1 has a buried depth of 950m, an oil layer thickness of 8m, an average porosity of 40%, an average permeability of 5000mD, an initial oil saturation of 0.6, a heterogeneous formation, and a crude oil viscosity of 2 × 10 under oil layer conditions. 4 mPa.s, the original pressure of the reservoir is 9.5MPa.
[0074] For 14 cycles of steam huff and puff in a horizontal well in the oil layer, the daily oil production reaches its peak and then continues to decline (the daily oil production peak is in the first cycle). From the analysis of the temperature profile test curve ( Figure 13 ) found that the second half of the well 1180-1260m had good steam absorption and high recovery, while the first half of the well had poor steam absorption, low recovery, and serious uneven steam absorption in horizontal wells. The temperature variation coefficient decreased continuously after reaching the maximum value at the end of the sixth cycle, dropped to 6.72 at the end of the ...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More