Method for reducing risks of thickened oil emulsification in process of reducing steam huff and puff

A heavy oil and steam technology, which is applied in the direction of earthwork drilling, wellbore/well components, production fluid, etc., can solve the problems that formation emulsification cannot be effectively solved, accelerate heavy oil emulsification, and frequent operation process, so as to reduce heavy oil emulsification Risk, strong operability, effect of improving effect

Active Publication Date: 2020-02-07
CHINA NAT OFFSHORE OIL CORP +1
View PDF6 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The reports of existing patents and scientific literature mainly focus on the emulsification mechanism and treatment after emulsification in the process of heavy oil cold recovery development, and solve the problem of emulsification of heavy oil in the wellbore after emulsification, but it is not effective for the problem of formation emulsification solve
In the process of steam stimulation, due to the high temperature of the injected fluid (usually around 300°C) and frequent operations (steam injection first, then spraying, and then pump production), the risk of heavy oil emulsification is accelerated. The existing cold recovery process It is difficult to solve the emulsification problem of steam huff and puff wells in heavy oil reservoirs

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for reducing risks of thickened oil emulsification in process of reducing steam huff and puff
  • Method for reducing risks of thickened oil emulsification in process of reducing steam huff and puff
  • Method for reducing risks of thickened oil emulsification in process of reducing steam huff and puff

Examples

Experimental program
Comparison scheme
Effect test

example

[0064] Implementation case 1: The third round of huff and puff drainage of well A23H in Lvda 27-2 oilfield in Bohai Sea was not timely resulting in emulsification and poor huff and puff effect.

[0065] Figure 12 It is the location of two steam huff and puff wells in Luda 27-2 oilfield.

[0066] Figure 13(a) shows the daily oil production and water cut curve of Well A23H in Lvda 27-2 Oilfield, which is divided into three stages: the natural energy depletion exploitation stage, the main goal is to determine the production capacity of cold recovery; the first round of steam huff and puff, injection Steam 4500m 3 , the bottom hole injection temperature is 340℃; the second round of steam huff and puff, injecting steam 5250m 3 , Bottom hole injection temperature is 340°C. The viscosity of degassed and dehydrated crude oil in Well A23H at 50°C was 2462mPa·s. After the second round of huff and puff well was opened, the production capacity dropped rapidly. After sampling, the visc...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a method for reducing risks of thickened oil emulsification in the process of reducing steam huff and puff. The method comprises the following steps that contents of colloid and asphaltene in a thickened oil sample are analyzed, and anemulsification mechanism of a target oilfield is determined through experiments; according to heat loss rate indexes in different stages of heat injection-soaking-blowing-pumping production, the best time to improve the liquid production speed of an oil well is determined; according to the injection temperature and the periodic steam injection volume, a stratum crude oil flow radius is evaluated, and the critical sand production speed VC of the target oilfield is taken as the highest value of the liquid discharge volume; after completion of soaking a well, a top choke is gradually opened, and the daily liquid production speed QL is maximized as much as possible (QL (Vc is required); after completion of automatic injection, an electric submersible pump is put into the well, and the pump frequency is increased gradually after the pump is started, high temperature liquid is discharged by taking the maximized daily liquid production capacity QLmax (QLmax (VC is required); and according to a CMG digifax software, influences of different liquid discharge velocities QL on periodic cumulative oil production are quantitatively evaluated, the bottom hole flow temperature TBHP with the different liquid discharge velocities is predicted, and a high temperature resistant electric submersible pump (temperature resistant Tmax of an electric pump) TBHP) is selected.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploitation, and particularly relates to a method of adjusting the frequency of an electric submersible pump and the size of an oil nozzle according to the effective free flow radius of the formation and the critical sand production rate in the optimal time window for steam injection thermal recovery wells. Without increasing the risk of sand production, increase the daily liquid production rate of the oil well, thereby reducing the risk of emulsification of heavy oil during steam stimulation. Background technique [0002] Thermal oil recovery technology (such as steam huff and puff, steam flooding, steam-assisted gravity drainage, etc.) is an effective technology that can greatly improve the recovery of heavy oil fields, and is an effective means of onshore heavy oil development. The Bohai Sea has a large scale of heavy oil reserves and a wide range of heavy oil viscosities (the viscosity of c...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/24
CPCE21B43/24
Inventor 刘东朱琴苏彦春马奎前刘宗宾蔡晖葛丽珍张风义胡廷惠王树涛
Owner CHINA NAT OFFSHORE OIL CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap