SU1435755A1 - Method of opening up a producing formation - Google Patents

Abstract

The invention relates to the drilling of oil and gas wells, the extraction of oil, gas and gas condensate, and allows for increased production by increasing the permeability of rocks and simultaneously improving the removal of the mudcake from the walls of the wells. The reservoir is drilled with a mud solution. Before the casing is lowered, an aqueous solution of aluminum sulphate with a concentration of 0.5 to 50% by weight is pumped into the interval of the productive formation and removed before the cementing begins. Cementation of the latter is carried out in the usual way. When a sulphate solution interacts with a mudcake, a paspymemie occurs on the well walls and a full wall of the crust occurs. Then the solution of the sulfate of apiumish penetrates gradually into the reservoir due to the pressure drop and diffusion, which prevents the formation of a new crust. In cases where clay material is present in the production layer, aluminum sulphate solution reacts with calcium-containing materials, destroys them and expands pores, cracks and channels. This leads to an increase in the productivity of the oil and gas reservoir. fi (L s 4 coded Nl JV JV

Description

The invention relates to the drilling of oil and gas wells, the extraction of oil, gas and gas condensate, namely, the method of opening the reservoir,

 The aim of the invention is to obtain a 1-fold productivity by increasing the permeability of the rocks and simultaneously improving the removal of the mudcake from the walls of wells,

The productive complex complex was drilled with a plain clay mud, before the production line was lowered. In the interval of the reservoir bed, an aluminum sulphate solution is injected with a concentration of 0.5–50 May,% at a density of 1000–1300 kg / m, and the production string is cemented in the usual way. During the discharge of the drill string, and The following processes, occur in the production well in the well in the interval of the productive bed,.

When an aluminum sulphate solution interacts with a mudcake on the wall, crust destruction occurs and the complete squeeze wall of the K1P {b from the last one. At the same time, in those cases when the production of W-SLEEP-carbonate reservoirs and sandstones, which include clay material (which is often common in practice), sulphate and aluminum solution intensively reacts with the above calcium-containing minerals, destroying them and fractures, cracks and channels of the productive formation. This whole process, occurring in the near-stream, part of a well, leads to an increase in the productivity of the oil-and-gas containing (as well as water, condensate) formation.

After the descent of the operation of the ion column, cementing is carried out according to the accepted technology. It is necessary to note that during the final flushing of the well before the cement: - the formation of a mudcake on the well machines does not occur again, since the walls of the well and the rock in the near part of the well are saturated with aluminum sulphate solution.

five

0

„

five

„

0

0

0

After the cementing of the production column is completed, in the presence of a difference in reservoir pressures in the seams in the interval of the bed of the complex of productive strata, annulus flows begin. However, due to the fact that in the range of the reservoir complex, all the permeability of the layers of the complex with a solution of aluminum sulfate, then. at the current flow, the cement mortar begins to mix with the aluminum sulphate solution coming out of the seams. Conducted; it has been established by laboratory work that when mixing the cement slurry with the sulphate solution of aluminum, a thick, immobile mass is instantly formed. At the same time, the setting time of the cement mortar is significantly reduced. This phenomenon quickly prevents erosion, separation of cement slurry and backflows in general. And in low-pressure, pro-ductile ipastah, this phenomenon prevents the spreading of cement mortar deep into the reservoir. It should be noted that in order to remove the mudcake from the walls of squashines, it is enough to pump a water solution of aluminum sulphate concentrate; 1-3 wt% However, for complex treatment of the wellbore part of the well in the interval of the productive formation (for expansion of pores, cracks due to the destruction of calcium-containing minerals and prevention of overflows) a more concentrated solution of aluminum sulfate is needed. For this reason, for the purpose of complex processing, the formations should be pumped into the well against productive formations. An aluminum solution of aluminum sulfate with a concentration of 20-50 wt.% g phi density of solution P50-1300 kg / m (the most recommended concentration).

The proposed method can be used to treat the wellbore zone of a well in a cased well in the perforation interval or in the open wellbore when there is no stubble of formation fluid or a weak influx of it. reservoir and crushed into the reservoir through pump-compressor e or drill pipe

After that, the wells are left to flow for a period of time from several hours to several days, depending on the concentration of the injected solution and the type of rocks that make up the reservoir.

The above processes occurring in the bottomhole zone in the interval of the productive formation when pumping an aqueous solution of aluminum sulfate with a concentration of 0.5-50 wt.%, Also give grounds for the following recommendations. This technology is recommended to be used to open the productive layers by drilling and perforation, as well as for injection into the productive

| formations, as a displacing agent, in order to increase oil recovery (and other fluids) and killing wells during major repairs,

Example. A well with a diameter of 215.9 mm was drilled to a depth of 2500 m with 1 washer with a mud solution. Productive layer is opened, starting from a depth of 2450 m. After working

wells up to the bottom in the range of 2440– 2500 m are injected with 3 m of an aqueous solution of aluminum sulfate of 30 wt.% concentration. The total time spent on the ejection of the drilling tool, the preparatory work, the descent of the production string, intermediate and final washings of the well is 48 hours. During this time, the Al2 (SO) aqueous solution is in contact with the reservoir.

Claims (1)

Invention Formula A method of opening the productive zone, including drilling of the productive formation, lowering the casing and cementing it, characterized in that, in order to increase productivity by increasing the permeability of the rocks and simultaneously improving the removal of the mudcake from the borehole walls, before lowering the casing into the productive formation zone Water solution of aluminum sulphate with a concentration of 0.5–5.0 wt.% is pumped in and pinched until the casing begins to cement.