Remediation of a hydrocarbon producing well bore in a subterranean formation includes injecting fluid containing self-degrading particulates into the well bore in order to stop production of hydrocarbon from the well bore prior to commencement of remedial operations and to temporarily seal the well bore from fluid transmission between the well bore and the formation prior to commencement of the remedial operations, and commencing the remedial operations upon the well bore. Examples of the remedial operations include injecting weighted fluid into the well bore, inserting a down-hole tool into the well bore, casing treatment, annulus treatment, well bore wall treatment, cementing, and refracturing. For refracturing, the fluid containing the self-degrading particulates can be injected until a down-hole pressure exceeds a fracture breakdown pressure of new fractures that will be produced by a perforating tool lowered into the well bore.

A method can include manufacturing particulate material during an operation at a well, injecting the particulate material into the well during the manufacturing, and changing a dimension of the particulate material during the injecting. Another method can include manufacturing particulate material during an operation at a well, injecting the particulate material and a proppant into the well during the manufacturing, and then the particulate material degrading in the well. Another method can include manufacturing particulate material during an operation at a well, fixing a shape of the particulate material by cooling the particulate material, and then injecting the particulate material into the well. A particulate material production and injection system for use with a well can include an extruder, and a pump connected between the extruder and the well. The pump pumps the particulate material into the well.

The invention pertains to a particulate composition suitable for self-healing concrete comprising limestone-forming bacteria or spores of limestone-forming bacteria and a bacterial nutrient dispersed in a lactic acid based oligomer matrix.

The invention also pertains to a method for manufacturing the particulate composition, comprising the steps of mixing a lactic acid based oligomer in the liquid phase with limestone-forming bacteria or spores of limestone-forming bacteria and a bacterial nutrient, and solidifying the resulting mixture to form solid particles. The mixing step is preferably carried out in an extruder. The formation of solid particles can be carried out in an under water pelletiser.

The invention pertains to a particulate composition suitable for self-healing concrete comprising limestone-forming bacteria or spores of limestone-forming bacteria and a bacterial nutrient dispersed in a lactic acid based oligomer matrix.

The invention also pertains to a method for manufacturing the particulate composition, comprising the steps of mixing a lactic acid based oligomer in the liquid phase with limestone-forming bacteria or spores of limestone-forming bacteria and a bacterial nutrient, and solidifying the resulting mixture to form solid particles. The mixing step is preferably carried out in an extruder. The formation of solid particles can be carried out in an under water pelletiser.