A Well Completion Method with the Function of Protecting Reservoir Isolation

Abstract

The invention relates to a well completion method with reservoir protection and packing functions. The well completion method primarily comprises the following steps that 1, well drilling is conducted, specifically, each reservoir is completely drilled through to the total depth or the reservoir is completely drilled through without reaching the total depth or the reservoir is incompletely drilled through; 2, well logging is conducted; 3, open hole perforation is conducted; 4, a barrier is built, specifically, the liquid barrier is built and designed in a well; 5, high-energy gas fracture is carried out, specifically, high-energy gas fracture is carried out on at least one reservoir one time, and artificial cracks are formed; 6, if each reservoir is completely drilled through without reaching the total depth or the reservoir is incompletely drilled through in the step 1, drilling continues till the total depth is reached; 7, well cementation is conducted, specifically, a cement ring is formed in the annular space between a casing pipe of each reservoir and the well; 8, casing pipe perforation is conducted, specifically, a duct between each reservoir and a shaft is built; and 9, the reservoirs are put into production or injection. The well completion method is short in construction period, small in number of procedures and low in cost. By means of the well completion method, the absorption and seepage capacities of the reservoirs can be greatly improved, and great economic benefits are achieved.

Description

technical field [0001] The invention belongs to the field of exploration and development of mineral resources such as petroleum, natural gas, coal bed methane, geothermal and in-situ leaching, and in particular relates to a well completion method with the function of protecting reservoir isolation. Background technique [0002] In the process of exploration and development of mineral resources such as oil, natural gas, coal bed methane, geothermal and in-situ leaching, casing perforation completion is the most extensive and most important well completion method at home and abroad. The so-called casing perforation completion is to drill through the reservoir to the completion depth, lower the reservoir casing to the bottom of the reservoir, inject cement slurry for cementing, and the cement slurry solidifies outside the reservoir casing to form a cement sheath (annular columnar Cement stone) plays the role of sealing the reservoir casing and sealing the reservoir, and then pe...

AI Technical Summary

Problems solved by technology

[0004] However, the above-mentioned reservoir stimulation measures will bring two problems: the first is the pressure penetration and the dissolved cement sheath; the second is that the artificial fractures generated in the near-wellbore area will exceed the reservoir and extend to other intervals above and below the reservoir

There are many disadvantages in methods such as swabbing, gas lift, and oil well pumping. One is that it is matched with oil testing, workover and oil production, and it is not within the scope of drilling engineering; the other is that the construction is completed by special equipment and special technology; Long, many processes, high cost

[0006] In the wellbore completed by casing perforation, high-energy gas fracturing has the following disadvantages: First, due to the limitation of perforation aperture, number of holes and hole density, the flow area formed by perforation is small, and it enters the reservoir near There is less high-pressure gas in the well area. In order to improve the fracturing effect of high-energy gas, the amount of gunpowder, the burning rate of gunpowder and the liquid block are often close to the limit value; The flow thickness of the gas entering the reservoir near the wellbore is also large; third, due to the small cross-section of the reservoir casing, the cross-section for the upward diffusion of high-pressure gas is also small

If it is directly applied to the open-hole reservoir, due to the reduction of the casing and the cement sheath, the limitation of the flow thickness of the perforation section is lost. First, it is difficult to control the artificial fractures, and the artificial fractures flow outward The probability and degree of extension increase; second, the debris of high-energy gas fracturing bombs may be left in the wellbore, which will bring disadvantages to cleaning the wellbore

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