Unlock instant, AI-driven research and patent intelligence for your innovation.

Downhole flow improvement

Inactive Publication Date: 2007-12-13
CONOCOPHILLIPS CO
View PDF19 Cites 11 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In general, increasing the molecular weight and concentration of the polymer in the drag reducer increases the effectiveness of the drag reducer, with the limitation that the polymer must be capable of dissolving into the host fluid.
However, drag reducers containing large concentrations of high molecular weight polymers generally can not be transported through small lines over large distances because the high viscosity of such drag reducers requires unacceptably high line pressures and / or the polymer particle size of such drag reducers can cause the lines to plug.
Thus, drag reducers have not been delivered to remote (e.g., subsea and / or downhole) locations because economical delivery to such remote locations typically requires passage through long conduits having small diameters.

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
  • Downhole flow improvement
  • Downhole flow improvement
  • Downhole flow improvement

Examples

Experimental program
Comparison scheme
Effect test

example 1

Emulsion Polymerization of 2-Ethylhexyl Methacrylate Using Redox Initiation

[0063]In this example, a drag-reducing initial latex was prepared. Generally, 2-ethylhexyl methacrylate was polymerized in an emulsion comprising water, surfactant, initiator, and a buffer.

[0064]More specifically, the polymerization was performed in a 300 mL jacketed reaction kettle with a condenser, mechanical stirrer, thermocouple, septum ports, and nitrogen inlets / outlets. The kettle was charged with 0.231 g of disodium hydrogenphosphate, 0.230 g of potassium dihydrogenphosphate, and 4.473 g of sodium dodecyl sulfonate. The kettle was purged with nitrogen overnight. Next, the kettle was charged with 125 g of deoxygenated HPLC-grade water, the kettle contents were stirred at 300 rpm, and the kettle temperature set to 5° C. using the circulating bath. The 2-ethylhexyl methacrylate monomer (100 mL, 88.5 g) was then purified to remove any polymerization inhibitor present, deoxygenated (by bubbling nitrogen gas...

example 2

[0068]In this example, the drag reduction capabilities of the 38% poly-2-ethylhexyl methacrylate polymer emulsion prepared in Example 1 were evaluated in a #2 diesel fuel system. The test device used in this example was a two inch Engineering Loop Re-circulation Test apparatus as shown in FIG. 5. This test allowed for the evaluation of drag reducer performance when injected in non-predissolved form into a hydrocarbon fluid in the flow loop. The test was used to simulate performance profiles and drag reducer behavior in field pipelines over a three-hour time period in terms of dissolution, peak performance, and degradation of the drag-reducing polymer.

[0069]In the two inch pipe-loop recirculation test, 600 gallons of diesel at 70° F. was recirculated from a mixed reservoir through a 2-inch diameter pipe loop and back to the reservoir. Approximate holdup in the pipe was 100 gallons. The diesel was recirculated at 42.3 gpm using a low-shear progressing cavity pump. Pressure drop was me...

example 3

[0079]Toluene (104.15 g) was added to a 600 ml beaker and the beaker placed under an overhead stirrer equipped with a 2 inch diameter 3-blade propeller. The stirrer was adjusted to 250 rpm and 41.675 grams of sorbitan sesquioleate (available as Lumisorb® SSO from Lambent Technologies, Skokie, Ill.) was added and mixed for 10 minutes until it dissolved. A portion of the emulsion prepared in Example 1 (104.175 g) was then added and the system mixed for 20 minutes. The composition had a density of 0.939 g / ml and a Brookfield LVDVII+ viscosity of 3700 mPa·s using a #4 spindle at 12 rpm. The composition in terms of percent by weight was as follows:

Emulsion from Example 141.67%Toluene41.66%Sorbitan sesquioleate16.67%

[0080]The dissolution rate of this material was measured using the dissolution rate test described above. The results show that the modified emulsion polymer had good dissolution properties which improve with increasing temperature.

Temperature, ° C.Dissolution Rate Constant, k...

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

A system for reducing pressure drop associated with turbulent fluid flow through conduits located in remote locations (e.g., deep under ground and / or deep under sea). Such reduction in pressure drop is accomplished by transporting a drag reducer through a long conduit of small diameter and thereafter injecting the drag reducer into a host fluid at the remote location, to make a treated fluid. The treated fluid is then extracted from the remote location via a production / transportation conduit. The presence of the drag reducer in the treated fluid reduces pressure drop associated with flow through the production / transportation conduit.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates generally to systems for producing fluids from subterranean formations. In another aspect, the invention involves downhole introduction of a drag reducer into a hydrocarbon-containing host fluid (e.g., crude oil) produced from a subterranean formation.[0003]2. Description of the Prior Art[0004]A variety of drag reducers have been used in the past to reduce pressure loss associated with turbulent flow of a fluid through a pipeline. Ultra-high molecular weight polymers are known to function well as drag reducers. In general, increasing the molecular weight and concentration of the polymer in the drag reducer increases the effectiveness of the drag reducer, with the limitation that the polymer must be capable of dissolving into the host fluid. However, drag reducers containing large concentrations of high molecular weight polymers generally can not be transported through small lines over large...

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): E21B43/22
CPCE21B43/12
Inventor HARRIS, WILLIAM F.EWEN, MARK D.BURDEN, TIMOTHY L.MILLIGAN, STUART N.SMITH, KENNETH W.JOHNSTON, RAY L.ANDERSON, VINCENT S.
Owner CONOCOPHILLIPS CO