# US 10,501,674 B2 · Enhanced activated sludge as drilling mud additive

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,501,674 B2
- Document ID: US10501674B2
- Status: Granted
- Kind: B2
- Application number: 16/032,386
- Filed: 2018-07-11
- Published: 2019-01-17
- Granted: 2019-12-10
- Earliest claimed: 2017-07-11
- Assignees: University of Louisiana at Lafayette
- Applicants: University of Louisiana at Lafayette
- Inventors: Gopi Chand Tripuraneni; Mark Zappi; Rafael Hernandez
- Web page: https://patentgrep.com/patent/US10501674B2

## CPC

- C09K 8/035: Organic additives
- C09K 8/32: Non-aqueous well-drilling compositions, e.g. oil-based
- C09K 8/487: Fluid loss control additives; Additives for reducing or preventing circulation loss
- C09K 8/506: containing organic compounds
- C09K 2208/34: Lubricant additives
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

In order to substantially reduce friction during drilling operations, specialized lubricants need to be added to drilling fluid recipes. In general, lubricants reduce friction by forming a thin film of liquid that separates the solid surfaces in contact. The primary objective of this research is to evaluate the performance of enhanced activated sludge (EAS) as a lubricant in drilling fluids. EAS is activated sludge rich in lipids. The mixed consortium of microorganism in waste water treatment facilities in grown under a high carbon/nitrogen ratio to trigger lipid accumulation. Performance of EAS as drilling fluid additive was compared with commercial lubricants in terms of lubricity and flow properties. Lubricants were evaluated using water-based drilling mud at lubricant concentrations of 1.78, 3.11, 4.43, and 6.17 pounds per barrel (ppb). Experiments were carried out in a standard lubricity meter. The lubricity meter tests the ability of the lubricant in the drilling mud to reduce friction. Other parameters measured were plastic viscosity, gel strength, fluid loss, mud cake thickness, sand content, methylene blue test (MBT), alkalinity, and chlorides. These findings show that EAS will improve the properties of water-based drilling mud.

## Claims

### Claim 1

A method of producing a drilling mud including the steps of:
(a) Obtaining a source of raw activated sludge;
(b) Fermenting the raw activated sludge under stress conditions to produce an enhanced activated sludge,
wherein said stress conditions include an environment relatively high in carbon compared to nitrogen;
(c) Removing water from the enhanced activated sludge; and
(d) Blending a quantity of the dewatered enhanced activated sludge into a base drilling mud to form a final drilling mud blend.

### Claim 2 (depends on 1)

The method of claim 1 wherein said environment consists of a synthetic media with a carbon to nitrogen molar ratio greater than 50 but less than 90.

### Claim 3 (depends on 2)

The method of claim 2, wherein the dewatered enhanced activated sludge content of a final drilling mud blend is greater than 3 pounds per barrel.

### Claim 4 (depends on 2)

The method of claim 2, wherein the dewatered enhanced activated sludge content of a final drilling mud blend is greater than 5 pounds per barrel.

### Claim 5 (depends on 2)

The method of claim 2, wherein the dewatered enhanced sludge content of a final drilling mud blend is greater than 6 pounds per barrel.

### Claim 6 (depends on 2)

The method of claim 2, wherein an API fluid loss reduction is greater than 10 percent when comparing a final drilling mud blend to the base mud.

### Claim 7 (depends on 2)

The method of claim 2, wherein a torque reduction is greater than 30 percent when comparing a final drilling mud blend to the base mud.

### Claim 8 (depends on 2)

The method of claim 2, wherein a decrease in a coefficient of friction is greater than 25 percent when comparing a final drilling mud blend to the base mud.