Offshore oilfield water injection well online one-step-process acidification technology

An offshore oilfield, single-step technology, applied in wellbore/well components, chemical instruments and methods, and production fluids, etc., can solve the problems of complex construction procedures, difficulty in optimal design of treatment fluid scale, time-consuming and labor-intensive, etc. To achieve the effect of simplifying the acid formula and construction process, realizing large-scale benefits, and saving the amount of acid

Active Publication Date: 2012-12-19
SOUTHWEST PETROLEUM UNIV +1
View PDF5 Cites 45 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] However, under the circumstances that the water injection wells in offshore oilfields are currently clogged on a large scale near the wellbore and the injection pressure is too high, the existing construction process of "injecting pre-fluid → injecting treatment fluid → injecting post-fluid → injecting displacement fluid" is exposed. Some disadvantages of poor adaptability to offshore oilfields: 1) The acid system is complex, there are many acid tanks and other auxiliary equipment, occupying a lot of space on ships and platforms, troublesome relocation, time-consumin

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
  • Offshore oilfield water injection well online one-step-process acidification technology
  • Offshore oilfield water injection well online one-step-process acidification technology
  • Offshore oilfield water injection well online one-step-process acidification technology

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] Embodiment 1: Taking the indoor simulation experiment of the core of Bozhong 25-1S oilfield of CNOOC as an example, the detailed description will be given.

[0047] Contaminated cores from the bottom of under-injection water injection wells in CNOOC Bozhong 25-1S Oilfield were used. The core is 3.542cm long, 2.52cm in diameter, with a porosity of 26% and a permeability of 1620×10 -3 μm 2 , to simulate the reservoir conditions, the acid fluid flow experiment was carried out at a temperature of 65°C and a confining pressure of 1 MPa. According to the injection sequence of "base fluid injection → single-step acid fluid injection → base fluid injection", the simulated acid fluid in The flow process of “water injection→injection of single-step plugging removal acid solution→water injection” in the formation.

[0048] The weight percentage of each component of the single-step acid solution used in the online single-step acidification: industrial acetic acid, 30%; industrial...

Embodiment 2

[0050] Example 2: Taking the online single-step acidification of layer C of water injection well QHD32-6-A7 in Qinhuangdao 32-6 oilfield of CNOOC as an example, it will be described in detail.

[0051] Well QHD32-6-A7 had a high injection pressure before acidizing layer C, the wellhead oil pressure was 8.9MPa, and the water injection rate was 10m 3 / h, and the injection pressure plus the net liquid column pressure tends to be greater than the formation fracture pressure. The research shows that the C layer of Well A7 is composed of suspended solids in the injected water, oil in the water and Fe(OH) 3 , CaCO 3 Scale caused blockage near the wellbore. In order to ensure the effective development of the oilfield, the on-line single-step acidizing technology is used for plug removal and injection enhancement.

[0052] QHD32-6-A7 water injection well C layer used in the online single-step acidification single-step acid liquid components weight percentage: industrial acetic acid,...

Embodiment 3

[0061] Example 3: Taking the QHD32-6-AW water injection well of CNOOC Qinhuangdao 32-6 Oilfield as an example, the online single-step acidification is described in detail.

[0062] The injection pressure of QHD32-6-AW water injection well before acidification is 9.5MPa, and the daily water injection volume is 22m 3 / h. Because the pump pressure is close to the rated working pressure, the injection is more difficult. The research shows that the AW well is injected with solid suspended solids, oil and Fe(OH) in the water. 3 , CaCO 3 Scale caused blockage near the wellbore.

[0063] QHD32-6-AW water injection well online single-step acidification acid liquid each component weight percent is the same as that of Example 2. A total of 30m prepared 3 Acid loading capacity is 30m 3 Skid mounted acid tank.

[0064] The online single-step acidizing process of QHD32-6-AW water injection well in CNOOC Qinhuangdao 32-6 oilfield is basically the same as that in Example 2, and the rati...

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

PropertyMeasurementUnit
Diameteraaaaaaaaaa
Permeabilityaaaaaaaaaa
Login to view more

Abstract

The invention relates to an offshore oilfield water injection well online one-step-process acidification technology, which comprises following steps of (1) preparing one-step acid liquor, wherein the one-step acid liquor consists of following components by weight percent: 20 to 40 percent of industrial acetic acid, 15 to 40 percent of industrial hydrochloric acid, 3 to 15 percent of deposition inhibitor, 5 to 15 percent of discharging aiding agent, 3 to 15 percent of corrosion inhibitor, 5 to 15 percent of antiswelling agent, 5 to 15 percent of iron ion stabilizer and 2 to 10 percent of hydrogen fluoride; (2) storing the acid liquor into an acid storage tank of an injection system, wherein the injection system consists of the acid storage tank, an acid resistant pump, a motor, a frequency converter, a flow sensor, a pressure sensor, a computer, a check valve, a three-way pipe and an acid injection pipe; (3) utilizing the acid resistant pump to pump the acid liquor into the water injection flow; (4) monitoring the variation of the pressure and the flow of the injected acid, and calculating skin coefficients in real time; and (5) keeping the water injection after stopping the acid injection. Due to the adoption of the offshore oilfield water injection well online one-step-process acidification technology, high efficiency, rapidness and large scale in plug removal of an offshore oilfield water injection well can be realized, the water injection pressure can be reduced, and the water injection quantity can be improved.

Description

Technical field [0001] The invention relates to an acidizing technology for water injection wells in downhole operations in offshore oil fields, in particular to an online single-step acidizing technology for efficiently and rapidly reducing wellhead injection pressure and improving water absorption capacity of water injection wells. technical background [0002] Offshore oilfield exploitation platforms have a limited lifespan (generally 20 years). In order to efficiently develop oilfields, as much formation crude oil as possible should be recovered within the lifespan of the platform, and water injection development methods should be adopted to increase the recovery rate and shorten the development time. [0003] With the increase of water injection time, the water injection wells in offshore oilfields gradually become clogged near the wellbore, resulting in a decrease in the water absorption capacity of the formation, an increase in the injection pressure, and a decrease in...

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
IPC IPC(8): E21B43/22C09K8/52
Inventor 刘平礼赵立强潘亿勇刘光成刘义刚贾云林山金城韩联合王天慧罗志锋
Owner SOUTHWEST PETROLEUM UNIV
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