1. The gas-liquid separate production string for the sulfur-containing gas well is characterized by comprising a casing 6, an electric submersible pump system 8 canned at the bottom of the casing 6, a liquid discharge oil pipe 5 and a gas production oil pipe 4 which are vertically arranged in the casing 6, wherein underground safety valves 3 are respectively arranged on the liquid discharge oil pipe 5 and the gas production oil pipe 4, and the safety valves 3 are connected with ground equipment through control pipelines 1; the canned submersible electric pump system 8 mainly comprises a gas-liquid separator 10, an electric submersible pump 9, an automatic reversing valve 7 and other components matched with the electric submersible pump 9, wherein the electric submersible pump 9 and the electric submersible pump 10 are connected with ground equipment through a cable 2.

2. A gas well gas-liquid separate production completion string according to claim 1, wherein said electric submersible pump 10 is located above said electric submersible pump 9.

3. A gas well gas-liquid separate production completion string according to claim 1, wherein the automatic reversing valve 7 and the electric submersible pump 9 are connected in series on the gas production pipe 4, and the reversing valve 7 is located on the electric submersible pump 9.

Background

In the process of exploiting the gas well, when the flow rate of the gas well is lower than the critical liquid-carrying gas flow rate, the gas well starts to accumulate liquid, the liquid accumulation in a shaft of the gas well can seriously limit the productivity of the gas well, and the water logging and production stop of the gas well can be caused when the liquid accumulation is serious. The liquid drainage gas production process is an effective method for solving the problem of gas well liquid accumulation.

At present, gas well liquid drainage technologies mainly comprise gas lift, foam drainage, plunger lift, an electric submersible pump and the like, under general conditions, the liquid drainage and gas production technologies can meet liquid drainage requirements of gas wells under different conditions, but most of the technologies are not suitable for the liquid drainage operation of sulfur-containing gas wells, particularly large-liquid-volume sulfur-containing gas wells, due to the special well body structure of the sulfur-containing gas wells.

The electric submersible pump is widely applied to the liquid drainage process of a conventional large-liquid-volume gas well, because the conventional gas well is basically not provided with an underground packer and is communicated with an oil sleeve annulus, most of the sulfur-containing gas wells are provided with the underground packer due to the requirements of safety and environmental protection, and the oil sleeve annulus is not communicated, the traditional electric submersible pump process can only simultaneously produce gas and liquid through an oil pipe, the efficiency of the electric pump is low when the gas and liquid are simultaneously produced, and the result of air lock and even pump burning can be generated under the condition of high gas-liquid ratio.

In order to solve the problems brought to the electric submersible pump process by gas-liquid simultaneous mining, the gas-liquid separate mining process is an effective solution.

The key point of realizing gas-liquid separate production lies in how to establish a gas-liquid separate production channel, and various gas-liquid separate production tubular column structures are proposed in the prior art, such as: patent CN110593846A discloses a gas-liquid separate production pipe column for liquid drainage and gas production of an offshore gas well, the process pipe column utilizes oil sleeve annulus to drain liquid after gas and liquid are separated underground, which is contrary to the idea that the sulfur-bearing gas well emphasizes the protection of a sleeve, and has great potential safety hazard, so the process pipe column is not suitable for the sulfur-bearing gas well; patent CN104047588A proposes a downhole gas-liquid separation column suitable for oil pumping well, but the process does not consider the protection of casing; patents CN2758474Y and CN201763310U also propose downhole gas-liquid separation columns, but these are not suitable for sour wells due to the well bore configuration and lack of casing protection.

Disclosure of Invention

The invention aims to provide a novel gas-liquid separate production tubular column for a sulfur-containing gas well, which can protect a sleeve and separate gas-liquid production and solve the problems of liquid accumulation and well flooding of the sulfur-containing gas well.

In order to solve the problems, the novel gas well gas-liquid separate production tubular column for the sulfur-containing gas well is realized by the following technical scheme:

a novel tubular column for gas well gas-liquid separate production of a sulfur-containing gas well comprises a casing, a canned electric submersible pump system arranged at the bottom of the casing, a gas production oil pipe and a liquid discharge oil pipe which are vertically arranged in the casing, wherein underground safety valves are further arranged on the gas production oil pipe and the liquid discharge oil pipe and are connected with ground equipment through control pipelines; the canned submersible electric pump system mainly comprises two submersible electric pumps, and an automatic reversing valve and a gas-liquid separator which are respectively matched with the submersible electric pumps, wherein the two submersible electric pumps are connected with ground equipment through cables.

The invention has the beneficial effects that: in the invention, corrosive fluid is not contacted with the casing all the time, thus conforming to the concept of the protective casing of the sulfur-containing gas well; in addition, the invention realizes the underground gas-liquid separate mining by using the canned electric submersible pump system, and avoids the damage to the electric submersible pump caused by the simultaneous gas-liquid mining.

Drawings

FIG. 1: the invention discloses a novel gas-liquid separate production tubular column structure schematic diagram for underground drainage gas production of a sulfur-containing gas well.

The attached drawings are marked as follows: 1. a control line; 2. a cable; 3. a downhole safety valve; 4. a gas production oil pipe; 5. a liquid discharge oil pipe; 6. a sleeve; 7. an automatic directional control valve; 8. canning the electric submersible pump system; 9. an electric submersible pump; 10. an electric submersible pump; 11. an annulus between the liquid discharge oil pipe and the tank body; 12. an electric submersible pump; 13. and (4) a packer.

Detailed Description

The invention is further illustrated by the following specific embodiments:

as shown in the attached figure 1, the novel underground gas-liquid separate production tubular column for water drainage and gas production of a sulfur-containing gas well comprises a casing 6, an electric submersible pump system 8 filled at the bottom of the casing 6, a liquid drainage oil pipe 5 and a gas production oil pipe 4 vertically arranged in the casing 6, wherein underground safety valves 3 are respectively arranged on the liquid drainage oil pipe 5 and the gas production oil pipe 4, and the safety valves 3 are connected with ground equipment through control pipelines 1; the canned submersible electric pump system 8 mainly comprises a gas-liquid separator 10, an electric submersible pump 9, an automatic reversing valve 7 and other components matched with the electric submersible pump 9, wherein the electric submersible pump 9 and the electric submersible pump 10 are connected with ground equipment through a cable 2.

The invention relates to a gas-liquid separate production novel tubular column working process and a method for underground drainage and gas production of a sulfur-containing gas well, which comprises the following steps:

the underground gas-liquid separate production pipe column is provided with an underground gas-liquid separate production channel which is constructed by a canned electric submersible pump system 8; after the electric submersible pump 10 is started, gas-liquid two-phase flow produced by an underground production zone is sucked into a gas-liquid separator 10 and is separated into rich liquid flow [ shown as a dotted line arrow in figure 1 ] and rich gas flow [ shown as a solid line arrow in figure 1 ], the separated rich liquid flow passes through the electric submersible pump 10 and then enters a liquid discharge oil pipe 5, and the separated rich gas flow enters an annular space 11, because density difference exists between gas and liquid, when the rich gas flow enters the annular space 11, a small amount of liquid is gathered at the bottom of the annular space 11, and when the accumulated liquid is too much, the lifting efficiency of the rich gas flow is seriously influenced, and aiming at the situation, the invention is designed as follows:

(1) when the liquid accumulation in the annular space 11 is not serious and the rich gas flow can be sprayed to the ground, the electric submersible pump 9 is closed, the side valve of the automatic reversing valve 7 matched with the electric submersible pump is opened, and at the moment, the rich gas flow can enter the gas production oil pipe 4 through the side valve.

(2) When the liquid accumulation in the annular space 11 is serious and the rich gas flow cannot be sprayed to the ground, the electric submersible pump 9 is opened to discharge the liquid, the side valve of the automatic reversing valve 7 matched with the electric submersible pump is closed, at the moment, the rich gas flow can enter the gas production oil pipe 4 through the electric submersible pump 9, and after the liquid accumulation is removed, the electric submersible pump 9 can be closed to recover the working mode of the step (1).

So far, gas-liquid separation mining has been realized.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.