Process Introduction

The injection production integration technology refers to the artificial lifting technology that uses one trip of string to realize heat injection and oil production. The string needs to meet the requirements of high temperature steam injection, blowout production and lifting oil production. The injection production integration technology saves the cost of string operation, avoids the heat loss caused by workover, and improves the production efficiency. According to the offshore demand, jet pump injection production integration, high-temperature electric pump injection production integration, bailing electric pump injection production integration and screw pump injection production integration technologies have been formed, which are suitable for heavy oil thermal recovery wells under different working conditions.

System Composition

Injection production integration technology is composed of pump, insulated tubing, high-temperature downhole tools, injection production conversion tools, special Christmas trees, hydraulic control pipelines, cables or small tubing, etc. Taking the injection production integration of jet pump as an example, it is compsed of jet pump, deep well safety valve and special Christmas tree. The core components of jet pump is mainly composed of working barrel, inner pump barrel and pump core.

Technical Index

Technology Applicability

Application

Since the large-scale application of jet pump injection-production integration technology in 2022, a total of 50 wells have been implemented in Bohai Oil Field. After three rounds of steam stimulation, it has helped the successful launch of the world's first large offshore development of ultra-heavy oilfield using thermal recovery. High-temperature ESP injection-production integration technology is being promoted and applied in a heavy oil field in Bohai Sea.

Process Introduction

Jet pump is a pump that relies on a certain pressure to spray out working fluid at a high speed through a nozzle.When the working fluid is ejected, a vacuum is formed at the inlet of the throat due to the surrounding air being swept away by the jet, and the transported fluid is immediately sucked in. Two fluids mix in the throat and exchange momentum, increasing the kinetic energy of the fluid being transported. Finally, most of the kinetic energy is converted into pressure energy through the diffusion tube. Jet pump is a pump that relies on a certain pressure to spray out working fluid at a high speed through a nozzle.When the working fluid is ejected, a vacuum is formed at the inlet of the throat due to the surrounding air being swept away by the jet, and the transported fluid is immediately sucked in. Two fluids mix in the throat and exchange momentum, increasing the kinetic energy of the fluid being transported. Finally, most of the kinetic energy is converted into pressure energy through the diffusion tube.

heavy oil thermal recovery:This technology is used for thermal recovery and development of ordinary heavy oil and ultra heavy oil. It achieves effective development of heavy oil through injection production integration process or SAGD process. Due to the absence of moving parts underground, the overall reliability is high.

Sand removal and oil recovery: In the production of oil wells in sand producing reservoirs, this technology uses concentric tube hydraulic jet pumps to switch production mode from sand control into sand carrying and discharging, thereby solving the problems of pump jamming, frequent pump inspection, and eccentric wear of pipes and rods in horizontal and directional wells in sand producing reservoirs.

drainage gas recovery：This technology is used for high water volume coal bed methane wells (over 150 cubic meters per day), directional wells, and horizontal wells . The purpose is to carry coal powder out of the well during draining, to prevent pump jamming and eccentric wear of rod and pipe.

Technology Applicability

Crude oil viscosity in reservoir 1-100000mPa·s

Jet pump temperature resistance ＜400℃

Jet pump core temperature resistance ＜250℃

Maximum gas content ≤90%

Maximum sand content ≤10%

maximum inclination ≤90°

Minimum curvature radius (dogleg degree) ≤36°/30m

Supporting products

Software: offshore jet pump lifting optimization design software, jet pump temperature and pressure monitoring software;

Products: Jet pump, deep well safety valve, pump core catcher, power fluid supply system, power fluid boosting system, jet pump temperature and pressure monitor.

Application

A super-heavy oil platform (crude oil viscosity exceeds 50000mPa · s) in a block of Bohai Oilfield has been put into production, with peak daily oil output of 1000m3/d and accumulative crude oil output of 500000t, bringing reserves to production, providing important support for the production increase in Bohai Oilfield.

Process Introduction

This technology uses coiled composite pipe cable to start and run the ESP unit. It does not need to move the pipe string when checking the pump, so it allows quick production, improve the operation efficiency and reduce the cost. It is suitable for steam huff puff wells, low viscosity heavy oil, marginal oil field without workover rig platform and cold recovery well lifting.

Technology Applicability

Discharge range: ≥100m3/d;

Pressure: ≤3000psi;

Casing pipe: 5-1/2", 7", 9-5/8";

Lift: ≤2000m;

Temperature: ≤180℃.

Supporting products

Tubing string: special wellhead, production packer, deep well safety valve and sliding sleeve;

Fishing part: continuous tubing cable, tubular packer, safety joint, steel wire cable and air release valve.

Application

In 2023, the application of the Rigless pump technology was carried out in a steam huff puff well in Bohai oilfield, successfully achieving integrated lifting of injection and production in heavy oil thermal recovery wells. The single round repair time was shortened by more than 40%, with a daily production of 110m3/d of liquid and 30m3/d of oil, receiving satisfactory results after application.

Process Introduction

The composition of the permanent magnet electric submersible pump is the same as that of a conventional electric submersible pump, consisting of a motor, protector, separator/gas handler, centrifugal pump, and connecting cable. Its advantage lies in the use of permanent magnets instead of copper bars in asynchronous motors for the rotor of permanent magnet motors, which does not require excitation, reduces energy conversion processes, lowers iron and copper losses. Permanent magnet electric submersible pump has higher power factor and motor efficiency compared to conventional submersible electric pumps.

Technology Applicability

Widely used in conventional cold and hot production wells

Oil wells with great changes in production capacity or unpredictable production capacity

Oil well with large inclination angle and limited length of lifting equipment

Small wellbore oil well

Oil wells with gradually increasing water content

Supporting products

Underground set: submerged permanent magnet motor, protector and submerged cable;

Downhole tools: SSSV, packer and cable shield;

Ground equipment: wellhead cable crossing and ground control cabinet.

Application

The permanent magnet electric submersible pump technology has been successfully used in conventional production wells and heavy oil cold recovery wells in Bohai Oilfield.

Process Introduction

Screw pump is a kind of artificial lifting equipment widely used in oilfield production, it belongs to the positive displacement pump. There are two types of screw pump that are currently used in the oilfield: downhole single screw pump and downhole twin screw pump.

Single screw pump: composed of a fixed rotor, the submersible motor drives the universal joint to drive the rotor around the stator center for planetary rotation to achieve liquid transportation. It has the characteristics of high pump efficiency, large head/lift, large viscosity application range, etc., suitable for small displacement, high sand content and other well conditions.

Twin screw pump: composed of a shell and two screw shafts meshing with each other, the submersible motor drives the synchronous gear to drive the main screw shaft meshing with each other and the slave screw shaft rotating at the same time to complete the liquid transmission. It has the characteristics of large displacement, large head/lift, high pump efficiency, compact structure, etc., suitable for heavy oil cold production, high gas bearing conditions and other well conditions.

Technology Applicability

Supporting products

Downhole equipment: submersible motor, protector, high voltage cable;

Downhole tools: downhole safety valve, packer, cable protector;

Ground equipment: wellhead cable crossing, ground control cabinet.

Application

In March 2023, a submersible single-screw pump was installed in a Bohai well to conduct a comparison test for lifting high-viscosity crude oil. The pump was hung at an inclined depth of 1722 meters with a well inclination of 51°, and the pump startup speed was 100 rpm. Compared to the centrifugal electric production before the measure, it reduced power consumption by 32%, demonstrating good energy-efficiency and adaptability to high-viscosity crude oil.