Lost circulation fluid treatment

Abstract

A method for separating fluid and fibrous lost circulation material from a mixture thereof that also includes drilled cuttings, the method including introducing the mixture onto a screen assembly that is vibrating for passage of the fluid and fibrous lost circulation material through the screen assembly and for separation of the driled cuttings from the fluid, the screen assembly with a plurality of screens one on top of the other and including at least a first screen and a second screen, one of the screens with a screen mesh with non-square openings as viewed from above to facilitate the passage of fibrous lost circulation material through the screen assembly.

Description

[0001] This is a continuation-in-part of U.S. Ser. No. 09 / 432,959 filed Nov. 8, 1999, and a continuation-in-part of U.S. application Ser. No.______ filed______ entitled "Lost Circulation Fluid Treatment" both co-owned with the present invention and application and both incorporated fully herein for all purposes.[0002] 1. Field of the Invention[0003] This invention is directed to methods for separating drilling fluid from a mixture of such fluid and lost circulation materials and to apparatuses useful in such methods.[0004] 2. Description of Related Art[0005] Often in drilling a wellbore, the circulation of drilling fluid to and then away from the drill bit ceases due to the porosity of the formation and / or due to fracturing of the formation through which the wellbore is being drilled. Drilling fluid pumps into the fractured formation rather than being returned to the surface. When circulation is lost, it is usually supposed that the lost circulation occurred at some specific depth w...

AI Technical Summary

Benefits of technology

0031] Such methods in which the resident time in a screen assembly of material that can sw

Problems solved by technology

In certain prior art screens that use square mesh openings fibrous lost cir

Images