US 4,764,231 A · Well stimulation process and low velocity explosive formulation

Abstract

Well stimulation involving use of a liquid explosive composition in the explosive fracturing of subterranean formations such as oil and gas bearing formations. An explosive formulation comprising a nitrate ester explosive component and a phlegmatizer component is introduced into a well penetrating the formation to be fractured. The phlegmatizer component is an alkyl or alkoxy diester which is mixable with the nitrate ester and can be varied in concentration to control the detonation velocity and maximum explosive pressure. Examples of phlegmatizing agents include alkyl or alkoxy alkyl esters of adipate or azelaic acids such as dibutoxyethyl adipate or diisobutyl azelate or polyethylene glycoxy-based diesters such as triethylene glycol dipelargonate. After the formulation is detonated to fracture the formation, the well is placed on production to recover hydrocarbons at an increased rate.

Claims35

Dependent claims

In the fracturing of a subterranean formation penetrated by a well, the method comprising:

(a) introducing into said well and into proximity to said subterranean formation a liquid explosive composition comprising a nitrate ester explosive component selected from the group consisting of nitroglycerine, ethylene glycol dinitrate, propylene glycol dinitrate, diethylene glycol dinitrate and trimethyl ethylethane trinitrate and mixtures thereof and a phlegmatizer component soluble in said liquid explosive component and having the formula:
##STR5## wherein R.sub.1 is a C.sub.4 -C.sub.9 alkyl group,
R.sub.2 and R.sub.3 are each independently alkyl or alkoxyalkyl groups containing from 3-11 carbon atoms,
R.sub.4 is a group, preferably ethyleneglycoxy or polyethyleneglycoxy, containing from 2-6 carbon atoms, and
R.sub.5 and R.sub.6 are each independently alkyl or alkoxyalkyl groups containing from 3-11 carbon atoms,
(b) detonating said explosive mixture to fracture said subterranean formation adjacent said well.

3 more elements

Dependencies are inferred from the claim text.

Well stimulation process and low velocity explosive formulation

Life of this patent

Well stimulation process and low velocity explosive formulation

Life of this patent

Abstract

Claims35