US3574319A

US3574319A - Paraffin control method

Info

Publication number: US3574319A
Application number: US889327A
Authority: US
Inventors: Charles E Morgenthaler
Original assignee: Tenneco Oil Co
Current assignee: Tenneco Oil Co
Priority date: 1969-12-30
Filing date: 1969-12-30
Publication date: 1971-04-13
Anticipated expiration: 1988-04-13

Abstract

A method for controlling paraffin deposition in an oil production system and includes injecting an asphaltic crude oil into paraffin base crude oil production and storage facilities. The invention includes the steps of mixing the asphaltic crude oil with the paraffin base crude oil and producing the paraffin base oil to the surface.

Description

United States Patent 2,300,348 10/1942 Dana 166/304X 2,303,823 12/1942 Coberly... 252/83 2,765,850 10/1956 Allen l66/304X 3,051,653 8/1962 Skolaut et al. 252/83 3,276,519 10/1966 Knox et al 252/8.3X

3,481,870 12/1969 Cheng et a1 166/304X OTHER REFERENCES Reistle, C.E., Jr.: Paraffin and Congealing-Oil Problems, Bureau of Mines Bulletin 348, US Govt. Printing Office, Washington DC, 1932, pp. 10 and 1 1. Copy in 166- 304 Primary Examiner-Stephen J. Novosad Attorneys Eugene S. Coddou and Lee R, Larkin ABSTRACT: A method for controlling paraffin deposition in an oil production system and includes injecting an asphaltic crude oil into paraffin base crude oil production and storage facilities. The invention includes the steps of mixing the asphaltic crude oil with the paraffin base crude oil and producing the paraffin base oil to the surface.

PARAFFIN CONTROL METHOD BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for preventing parafiin deposition in conveying and storage facilities of paraffin base oil. More particularly, the invention relates to the inhibition of paraffin deposition in an oil well production system by addition of certain wax crystal modifiers to a production stream of paraffin base oil.

2. Description of the Prior Art In many parts of the world paraffin crude oils exist and are produced with resulting deposition of paraffin in the production tubing, surface lines and tanks. There are various remedies to inhibit or prevent this deposition, but none have been entirely satisfactory.

Prior art methods used to solve this problem have been either preventative or curative. Preventative technology includes such methods as addition of naphthalene and various other solvents or washes to clean up tubing, rods and pipes when they have become plugged. Such techniques have not been universally successful. In recent years some information has been published which shows that rods coated with polyethylene exhibit a resistance to fouling. Several cases have been described wherein fine particles of polyethylene are injected into the hole to prevent deposition of paraffin in the production tubing.

I-Iot oil treatments and solvents have been used in an attempt to melt paraffin which has been deposited on the interior of lines in the production system. Scraping operations have been used to physically remove the deposits from piping and storage facilities.

The expense associated with all of the prior art methods becomes very great as wells become deeper and the length of the downhole tubing becomes greater. The cost of chemicals and labor employed in such operations in prior arts is extremely burdensome and shows the need for an inexpensive improvement in these procedures.

SUMMARY OF THE INVENTION An object of this invention is to provide an improved method for preventing paraffin deposition in storage and conveying equipment associated with a producing oil well.

Briefly stated, this invention is an improved method for preventing paraffin deposition in a paraffin base crude oil conveying and storing system. It includes the steps of injecting an asphaltic crude oil into the paraffin base crude oil and commingling the asphaltic crude oil with the paraffin base crude oil. In certain embodiments, the asphaltic crude oil is injected continuously into the conveying and storage system. In certain other embodiments the asphaltic crude oil is injected periodically in slugs into the conveying and storage system.

In certain other embodiments a method for preventing paraffin deposition in a system for producing paraffin base oil DESCRIPTION OF THE PREFERRED EMBODIMENT production pipe. The presence of the asp altic Oil in the paraffinic oil inhibits the deposition of paraffin during production and storage. If paraffin deposition has been no problem in the production tubing from the formation to the wellhead, then the location of injection of the asphaltic oil should be at some point upstream of anticipated or previously observed deposition. The injection of the asphaltic crude oil should inhibit subsequent precipitation of paraffin in any conveying or storage equipment.

It is to be understood that the preferred asphaltic crude oil will produce no asphaltene precipitate when mixed with the paraffinic stream. 7, 7

It is believed that this deposition control is accomplished because of a crystalline state modification of the paraffin by the asphalt or by some specific physical or chemical property of the asphaltic crude oil. In other words, some degree of wax crystal modification is accomplished by the addition of the asphaltic crude oil. Another explanation for this phenomenon is that the asphaltic oil may act as a polar or film-forming agent on the metal surface in the production and storage equipment.

It is to be understood that the foregoing is generally illustrative of the invention, and that other alternatives and embodiments will become obvious to one skilled in the art after studying this description. The description, therefore, is to be construed as illustrative only of certain embodiments of the invention.

We claim:

1. In a method for preventing paraffin deposition in a paraffin base crude oil conveying system, the combination of steps comprising:

injecting an asphaltic crude oil into said paraffin base crude oil; and

commingling said asphaltic crude oil with said paraffin base crude oil prior to flowing of said mixture through said system.

2. The invention as claimed in claim 1 wherein; said asphaltic crude oil is a heavy asphaltic Wyoming crude oil.

3. The invention as claimed in claim 1 wherein; said asphaltic crude oil is injected continuously into said conveying system.

4. The invention as claimed in claim 1 wherein; said asphaltic crude oil is injected periodically in slugs into said conveying system.

5. In a method for preventing paraffin deposition in a system for producing paraffin base oil from an underground formation penetrated by a wellbore, the combination comprising:

conveying an asphaltic crude oil from a storage means to the annulus of a production pipe situated within said producing underground formation;

injecting said asphaltic crude oil into said paraffin base production stream;

commingling said added asphaltic crude oil with said paraffin base production stream; and

producing said paraffin base oil stream to the surface.

6. The invention as claimed in claim 5 wherein; said asphaltic crude oil is a heavy asphaltic Wyoming crude oil.

7. The invention as claimed in claim 5 wherein; said injection step includes continuously injecting said asphaltic crude oil into sa paraffin base production stream.

8. The invention as claimed in claim 5 wherein; said injection step includes periodically injecting said asphaltic crude oil into said paraffin base production stream.

Claims

2. The invention as claimed in claim 1 wherein; said asphaltic crude oil is a heavy asphaltic Wyoming crude oil.
3. The invention as claimed in claim 1 wherein; said asphaltic crude oil is injected continuously into said conveying system.
4. The invention as claimed in claim 1 wherein; said asphaltic crude oil is injected periodically in slugs into said conveying system.
5. In a method for preventing paraffin deposition in a system for producing paraffin base oil from an underground formation penetrated by a wellbore, the combination comprising: conveying an asphaltic crude oil from a storage means to the annulus of a production pipe situated within said producing underground formation; injecting said asphaltic crude oil into said paraffin base production stream; commingling said added asphaltic crude oil with said paraffin base production stream; and producing said paraffin base oil stream to the surface.
6. The invention as claimed in claim 5 wherein; said asphaltic crude oil is a heavy asphaltic Wyoming crude oil.
7. The invention as claimed in claim 5 wherein; said injection step includes continuously injecting said asphaltic crude oil into sa paraffin base production stream. 8. The invention as claimed in claim 5 wherein; said injection step includes periodically injecting said asphaltic crude oil into said paraffin base production stream.