UA25925U - Method for insulation of formation waters flooding in wells - Google Patents

Abstract

A method for insulation of formation waters flooding in wells includes delivery of plugging material to the well and its pumping under pressure not higher that the formation pressure into the bed. Plugging material is delivered to productive bed by tube space, and its squeezing into the bed under pressure is made after lifting tubings at calculated depth.

Description

Description of the invention

The useful model applies to the oil and gas industry, in particular to methods of isolating the inflow of 2 formation waters in oil and gas wells.

A well-known method of isolating formation water inflow in a well (prototype), which includes the delivery of plugging material to the well with simultaneous sampling of its products, before stopping the selection of products, the plugging material is delivered through the annular space to the productive formation under pressure that does not exaggerate the formation and the plugging material is pumped into layer | see and. with. USSR Mo1329243 IPC 4 70. E21В43/32, publ. 10.02.2000).

The disadvantage of the prototype method is that it does not provide the necessary quality and reliability of insulation. During the injection of backfilling material (solarbentonite mixture) into the well through the annular space with the creation of excess pressure necessary to push the backfilling material into the formation, a plug may form in the pump-compressor pipes (tubes) due to the fact that the cement will settle and be compressed 72 in the lower part of the pipeline and after the end of the insulation work, if you try to wash the remains of the tamponage material through the pipeline, you may not get the necessary circulation. In addition, after carrying out the isolation work, it is necessary to leave the well to wait for the hardening of the cement to create a high-quality screen from the inflow of formation water, since during operation the unhardened plugging material will get into the pipeline, which can lead to an emergency situation.

The disadvantage of the method according to the prototype is also the limitation of its application at depths of more than 2000 Ohm, which consists in the fact that during the injection of tamping material into the well through the annular space, film and drip water from the walls of the pipes through which it is pumped enters the solar bentonite mixture, and when even a small amount of water (5-1095) in the solar bentonite mixture causes a loss of pumpability and creates a plug in the well.

The purpose of the useful model is to increase the reliability and quality of isolation of formation water inflow into the well and to expand the technological possibilities of using the method in wells with a depth of up to 5000 m.

To solve the problem, a method of isolating the inflow of formation water into the well is proposed, which includes the delivery of plugging material into the well and pumping it into the formation under a pressure that does not exceed the formation pressure, according to a useful model, the plugging material is delivered to the productive formation through the pipe space, and its crushing into the reservoir under pressure is carried out after raising the pump-compressor Ha pipes to the calculated depth.

Mixtures of various chemical additives to clay and cement compositions (polyacrylamide, liquid glass, various acids, alkaline solutions, oil, (3 diesel fuel, etc.)) are used as tamponage materials for the isolation of water inflows, which, upon contact with formation waters, enter into a chemical reaction and create a waterproof screen. p

Depending on the required volume of backfilling material, the depth of rise of the tubing is calculated, while the buffer fluids, which according to the cementing technology must be pumped in before and after the delivery of backfilling material, create a barrier for the pressing fluid and prevent it from mixing with "backfilling material that makes it possible to avoid the occurrence of traffic jams during the next pressing of the tamponage material into the productive layer under pressure. At the same time, the contact surface of the tamponage material with film and dripping liquids is significantly reduced, which also reduces the possibility of traffic jams.

From" According to the method according to the prototype, large volumes of tamponage material and thrust fluid are required for delivery of tamponage material through the annular space, which in turn increases the time of delivery of tamponage material to the productive layer. In addition, the tamponage material is mixed with buffer liquids and, due to its properties, is deposited on the walls of the production column, which worsens the conditions for its operation. sl According to the proposed method, it is proposed to deliver the tamponage material to the productive layer through the pipe space, while, in comparison with the prototype, its delivery time is reduced by 3-5 times due to the reduction of the volumes of both the pressing fluid and the tamponage material itself, which makes it possible to use the method at depths of up to 500Ω.

The method of isolating formation water inflow into the well (hereinafter referred to as the method) is carried out as follows. sl The tamponage material is prepared in a container directly near the well. Through the pipe space of the tubing, the plugging material is delivered to the productive layer by a cementing unit. Injection into the formation under pressure that does not exceed the formation pressure is carried out with a cementing unit after raising the tubing to the 25th calculated depth. The compression pressure of the tamponage material into the productive layer is calculated based on the formation pressure and the pressing pressure of the production column. The rise height of the tubing is calculated depending on the volume of the plugging material delivered to the productive layer. Before and after pumping the calculated volume of tamponage material, the given volumes of buffer liquids (diesel fuel in the range from 0О.См3 to 0.Вм3) and the correspondingly calculated volume of the thrust liquid are pumped through the tubing string. bo An example of using the method.

Waterproofing works were carried out on well 101 of the Stepovoy GKR due to the fact that the well was not producing due to waterlogging and a drop in formation pressure. The productive layer is located at a depth of 4886-4875m. The reservoir pressure is 25.3 MPa, the pressing pressure of the production column is 44.0 MPa. The diameter of the operating column is 168x14 mm, the tubing with a diameter of 7 mm is lowered to a depth of 4888 m. 65 As a tamponage material, a solar bentonite mixture was used, the calculated volume of which was

1.8m3. Before pumping the tamponage material, the first volume of buffer liquid was used - 0.5 m of diesel fuel, and after pumping the tamponage material, the second volume of buffer liquid - O0.bm? diesel fuel The volume of the pressing fluid was 13.4 m3.

After pumping the backfill material into the well through the pipe space, the tubing string was raised to the calculated depth, which was 4650 m, and to remove the remains of the backfill material from the tubing string, a backwash was performed in a volume equal to the volume of the tubing. Pumping and pressing of the backfill material into the productive layer was carried out with the TSA-320 M cementing unit. After pumping the backfill material into the well, the pipe space was closed with a valve or ball valve and 70 TSA-320 M cementing units created a pressure of 140 MPa. A 1.8 m volume of solar bentonite mixture was pumped into the formation and left under this pressure for the entire period of the OZC, which was two days.

After the development of the well, they received an industrial gas flow of 13.5 thousand cubic meters per day at pipe pressures of 18.4MPa and annular pressures of 144MPa.

The technical result of the application of the developed method of isolation of reservoir water inflow into the 72 well is an increase in its quality and reliability and an expansion of the technological possibilities of application during the isolation works, which ensures the preservation of reservoir properties and an increase in hydrocarbon production, a reduction in the probability of emergency situations and a reduction in costs during repair - insulation works.

Claims (1)

The formula of the invention is a method of isolating the inflow of formation water into the well, which includes the delivery of plugging material into the well and pumping it into the formation under a pressure that does not exceed the formation pressure, which is characterized by the fact that the plugging material is delivered to the productive formation through the pipe space, and its crushing in - layer under pressure is carried out after raising the pump-compressor pipes to the calculated depth. Official bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2007, M 13, 27.08.2007. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. sch (o) IF) p - and? name) 1 se) name) sl 60 b5