Surge chamber assembly and method for perforating in dynamic underbalanced conditions

A surge chamber assembly for use in a wellbore, the surge chamber assembly comprising:

• a housing having first and second openings, a surge chamber and a pair of combustion chambers oppositely disposed relative to the surge chamber, the openings providing fluid communication between the exterior of the housing and the surge chamber;
• first and second sleeves slidably positioned within the housing relative to the first and second openings, respectively, each sleeve having a first position wherein fluid communication through the relative opening is prevented and a second position wherein fluid communication through the relative opening is allowed;
• and
• a combustible element positioned in each of the combustion chambers such that combusting each of the combustible elements actuates one of the sleeves from the first position to the second position.

A downhole tool for use within a wellbore, the downhole tool comprising:

• a housing having a combustion chamber positioned therein;
• a combustible element positioned in the combustion chambers;
• an explosive positioned within the housing relative to the combustible element;
• and
• an actuable member having first and second operating configurations, wherein the explosive is used to ignite the combustible element and wherein the actuable member is actuated from the first operating configuration to the second operating configuration responsive to combustion of the combustible element.

A method for actuating a downhole tool comprising the steps of:

• disposing a combustible element within a combustion chamber of the downhole tool;
• positioning the downhole tool within a wellbore;
• explosively igniting the combustible element;
• and
• combusting the combustible element to actuate the downhole tool from a first operating configuration to a second operating configuration.

A tool string for use in a wellbore comprising:

• first and second surge chamber assemblies;
• and
• at least one perforating gun positioned between the first and second surge chamber assemblies,
• wherein each of the first and second surge chamber assemblies comprises:
• a housing having an opening, a surge chamber and a combustion chamber, the opening providing fluid communication between the exterior of the housing and the surge chamber;
• a sleeve slidably positioned within the housing having a first position wherein fluid communication through the opening is prevented and a second position wherein fluid communication through the opening is allowed;
• and a combustible element positioned in the combustion chamber such that combusting the combustible element actuates the sleeve from the first position to the second position.