WO2020088732A1 - Jet pump for the gases self relief of petroleum wells - Google Patents

Abstract

The new invention relates to a well self-relief with no man intervention or underlying danger, e.g. environment pollution. Whereby, gas amounts can be maintained and pumped with oil to a pooling station, which is the desired aim. This is achievable by applying a theory of jet pumping system (fig no. 4). Having all required tests and investigation done on a well at question, a proper production hole is delimited to be used as a surface nozzle (2, fig no. 3) and (2, fig no. 4) onto production line (pumping discharging) (1, fig no. 3). It is arranged for accelerating oil flow generated, lowering pressure in a downstream nozzle area (3, fig no. 3) and (3, fig no. 4) and thus being under a vacuum. A gas-relief passage (6, fig no. 3) is to be extended from its annular space (5, fig no 3). By providing both a check valve (7, fig no. 3) and regulating valve, gases are withdrawn from the annulus (5, fig no. 3) to be well mixed with oil in the production line. The aforesaid well-mixing guarantees the smooth flow of oil heading to the production plant and as much as possible a lower pressure of the annulus. Accordingly, the annulus gases are to be relieved with no man intervention while adjusting ideal conditions and pressure level for well-operated pump and non-stop un fluctuating production process.

Description

Jet Pump for the Gases Self Relief of Petroleum Wells

Technical Field

Petroleum wells are of two types:

1. Flowing wells (the pressure of petroleum-borne layer is sufficient for its smooth flow up to the well surface towards a collection station)

2. Non-flowing wells (the pressure of petroleum-borne layer is not sufficient for its flow up to the well surface towards a collection station. It depends on artificial lift)

- Using centrifugal electric submersible pumps is the most conventional method worldwide applied.

- This method depends on the fact that separation and relief of petroleum- associated gases is a must using manual techniques. Otherwise, such gases are to be gathered and burned off.

Background Art:

Petroleum is produced from non-flowing wells via artificial lift system, the most important of which is centrifugal electric submersible pumps (fig no.l)

Oil well production is controlled using a set of wellhead valves, called wellhead assembly (charismas tree). (6 of fig no. 1)

For a pump (3, fig no. 1) of high efficiency, separation of oil-associated gases is a must, before reaching a down hole pump suction opening. This is achieved by installing mechanical-gas separator ( 2, fig no. 1) onto the pump (3, fig no. 2), having its own motion from the same pump jack.

Mechanical-gas separator acts on separating petroleum-associated gases upstream of a pump inlet (3, fig no. 2) to be ejected into the annulus (4, fig no. 1) between production pipeline strings (pump discharge) and well wall. These gases are removed by a connection of annulus passage (3, fig no. 2) through a wellhead assembly (Charismas tree) (6, fig no. 2) with pump discharging path via a check valve (4, fig no. 2)and regulating valve.

Thereby, gas and petroleum (oil) streams are driven into a collecting station averting the way to the pump.

- As such, gases are discharged from an annulus (3, fig no. 2) to a production line ( 1, fig no. 2); offsetting the annulus-gas pressure against product line pressure (pressure of surface-discharging pump).

- However, such pressure is not sufficient for all down hole separated gases be disposed of merely by using mechanic separator (2, fig no. 1). This causes gases infiltration into the pump suction, causing the pump malfunctioning, damage of its parts, shortage of production and ultimately leading to its breakdown.

- In such event, the annulus-suspending gases must be cleared off and

pressure lowered by opening an open air passage to the annulus (3, fig no. 2) via wellhead assembly. Thereby, the annulus pressure becomes as low as possible, i.e atmospheric pressure. Then, the well is re-operated. This is called well gases relief into open air.

- Such process is of hazardous consequences; pollution of surrounding

environment- loss of huge amounts of gas.

Problems to be solved

- A well gas relief (3, fig no. 2), for maintaining the annular space and down hole pressure almost near atmospheric pressure, results in higher production of the well.

- A progressive increase of annular space pressure (3 fig no. 2), out from

gases separation, has a negative impact on pump performance (3, fig no. 1), thus gradual decrease of well productivity till its halt, depending on pressure, amounts of separated gases displacing oil surface and entering into pump suction. - Thus, well productivity shall be fluctuating its ongoing operation is based on good follow-up, regular gas relief and clearance, in other words, depends on manpower who would be prone to all concomitant risks- surround environment pollution- loss of gas amounts.

Disclosure of the Invention:

- Being at the top of the world metal wealth, on which most industries are based, whether derived therefrom and which use it as a fuel, Petroleum is one of the most important source of energy. Besides petrol products extracted therefrom, Petroleum is the backbone of industry.

- It is also considered a national income for the country. Thus, it is given

much attention for its drilling and refining as well as its preparation whether for refining or exporting.

- Petroleum companies assume a critical role as a source of national income, i.e. generating hard currency, upon selling the product, whether crude or in form of petrol products.

- There are various and big-scale petroleum-dependent processes are

performed, staring from its exploration, drilling, mining and ultimately treatment process.

- Underground mining of oil is done by one of the following methods:

- Natural flow of layers (flowing well)

- Artificial lift (non-flowing well)

- Artificial lift is an essential technique in the field of non-flowing well

production. The most important, worldwide applied method thereof is downhole centrifugal electric submersible pumps (fig no. 1)

Specifications of pumps are determined based on a well volumetric productivity, descriptions of petrol oil produced in respect of its composition of water, gas, density and viscosity of such elements, impurities content (sand), depth of generating formation layer, oil temperature, pressure of formation layer. - The above artificial lift using centrifugal electric submersible pumps (3, fig no. 1) mainly requires oil/petroleum gases be separated and not allowing such gases to enter pump suction inlet. That is, in turn, will result in proper conditions for pump operation and not to be subject to breakdown or damage of its parts.

- This is achieved by installing mechanical-gas separator onto the pump,

having its own motion from the same pump jack.

- Mechanical-gas separator acts on separating oil-associated gases upstream of a pump inlet to be pooled into the annular space between oil pipes and well wall.

- Therefore, the annulus gas relief is a crucial and essential process for

maintaining oil surface level in the well bottom while preventing the leakage of separated gases into pump suction inlet.

- This is done via a connection extending from the annulus passage to the pump discharging route (production pipeline) through a wellhead assembly (charismas tree) via a check valve and regulating valve. Whereby, oil/petroleum streams are not to be driven into the annular space and then settled into the well bottom, so that pressure of production line is balanced against the annulus pressure at the well surface. By doing so, the gas-relief will then be completed.

- The pressure of production line is often higher than that of well-surface, which disallowing full relief of separated gases.

Having a well on operation for a short period, separated gases are expected to be accumulated in the annular space, thus increasing the oil surface pressure, and reach the pump suction inlet. This will eventually lead to the pump breakdown and damage for its parts.

- As a result, non- intermittent relief of separated gases can be achievable with no man intervention or causing environment pollution out from discharging gases into open air. - A jet pumping system entails using a production hole delimited beforehand along with well tests at the well surface as a nozzle for a jet pump. This will accelerate produced oil streams (transferring pressure into kinetic energy), and establish a vacuum area that is useful in withdrawing and relieving separated annulus gases.

- Wherein, at the beginning of pilot well operation, production holes of

different diameters are on test in an attempt to determine a proper hole configured to

provide high production with lowest level of water and stable pressure of formation layer.

- By selecting production hole, acting as an nozzle, a jet pump is of proper design by setting a vacuum area and determining diameter and length of mixing pipe. A kinetic energy is to be converted into a pressure as a result of good mixing of gases with oil.

- By connecting gas-relief route through a wellhead assembly (charismas tree) with vacuum area of jet pump connected with the production line (pump discharging) via a check valve and regulating valve, oil streams creates a vacuum medium allowing gases out from the annulus be relieved and mixed well with oil in production line heading towards a collection station.

- Accordingly, the annulus gases are to be relieved with no man intervention while adjusting ideal conditions and pressure level for well-operated pump and non-stop unfluctuating production process

- Benefits of well gases self-relief

- No intervention of man factor.

- Continuous production with no need for stopping the pump because of

gases.

- Maintenance of pump parts in a good condition.

- Not causing environment pollution. - No loss of gas amount

- Well-mixing of gas with oil in the production line and smooth flow thereof.

Description of jet pump

1- A nozzle (production hole of the well) converting pressure into kinetic

energy generating lower pressure and a vacuum area.

2- Mixing pipe is a part of pipe having a diameter proportional to that of

production hole and proper length for allowing well-mixing of gases with oil.

3- Connection configured to convert kinetic energy into pressure.

Applicability

- Well gas relief and withdrawal of separated gases upon using artificial lift using centrifugal electric submersible pumps. This is so important for pump maintenance in good condition having higher efficiency and ongoing operation.

- The well Production hole is to be used for converting pressure exerted

thereon into a velocity (kinetic energy), thus generating a vacuum.

- Based on the production hole diameter, the rest parts of jet pumps are

designed in terms of diameter, mixing pipe length, speed lowering connection (converting kinetic energy into pressure)

- All required parts and items are domestically manufactured.

Brief Description of drawing;

Drawing Board #1

Fig (1) Electric motor

Fig (2) Mechanical gas separator

Fig (3) Submersible pump Fig (4) annulus

Fig (5) Christmas Tree

Fig (6) Production pipeline

Fig (7) Electric operating panel

Fig (8) transformer

Drawing Board #2

Fig (1) Production pipeline

Fig (2) Production nozzle

Fig (3) annulus

Fig (4) One-way valve

Fig (5) gas relief line

Fig (6) Christmas Tree

Drawing Board #3

Fig (1) Production tubes

Fig (2) Production nozzle

Fig (3) vacuum space

Fig (4) mixing pipe - speed lowering connection

Fig (5) annulus

Fig (6) gas relief line

Fig (7) One-way valve

Fig (8) Christmas Tree Drawing Board #4

Fig (1) Entry hole Fig (2) nozzle Fig (3) vacuum space Fig (4) vacuum hole Fig (5) mixing pipe Fig (5) exit hole

Claims

Claims

1- A jet pump configured to gases self-relief of petroleum wells with reference to the figure, comprising the following parts:

a. Oil stream inlet (petroleum produced out from the well using a submersible pump),

b. A nozzle ( a selected production hole depending on well-tests) converting the oil pressure energy into kinetic energy, thus generating a vacuum.

c. A vacuum space or area resulted from the high speed of oil flow from nozzle outlet.

d. A withdrawal hole for withdrawing gases emitted from the well annulus (separated via a mechanical separator below the submersible pump).

e. A mixing pipe for input oil be mixed with withdrawn gases.

f. A exit outlet (of bigger tapering diameter than that of mixing pipe wherein oil and gas flow energy is converted into a pressure energy).

2. The jet pump according to the first claim, wherein an inlet of the said jet pump is connected to the wellhead production line, the said nozzle works on converting the oil pressure energy into a speed energy, thus generating a vacuum downstream of the said nozzle in the annulus in communication with the withdrawal hole.

3. The jet pump according to the first claim, wherein the withdrawal hole (a vacuum area) is connected to the wellhead separated gases relief line.

4. The jet pump according the first claim, wherein input oil is well-mixed with withdrawn gases from the withdrawal hole via passing through the mixing pipe.

5. The jet pump according to the first claim, wherein the kinetic energy of gas- oil mixture, coming out of the mixing pipe, is converted into a pressure energy via the exit outlet set, due to gradual increase of diameter (an area of transferring kinetic energy into pressure).

6. The jet pump according to claims 1-5, wherein it is activated via the oil pressure, wherein the annulus separated gases are withdrawn and well mixed with oil, then such mixture is smoothly driven into the collection station. This will result in maintaining the well production rate; higher performance of submersible pump while protecting its constituting parts; saving and using amounts of separated gases; protecting environment from gases or burning gases pollution and securing well-gas relief without man intervention.