Method for primary cementing a well with a drilling mud which may be converted to cement using chemical initiators with or without additional irradiation

A method for drilling and primary cementing a well comprising the steps of:

• drilling a well using a hollow drill string having a drill bit with at least one orifice communicating between the inside of the hollow drill string and the outside and located at the lower end of said drill string so as to produce a wellbore,
• circulating, while drilling, a drilling fluid comprising:
• at least one polymeric material containing at least one double bond and capable of being cross-linked with a monomeric cross-linking agent, said polymeric material being selected from the group consisting of:
• vinyl-, hydroxyl-, carboxyl-terminated butadiene acrylonitrile copolymers, metharylic acid-methacrylate ester copolymers;
• polyethylene;
• polyacrylamide;
• polybutadiene;
• hydroxyl- or carboxyl-terminated polybutadiene;
• hydroxyl-terminated epichlorohydrin polymers;
• polybutadiene oxide;
• polyvinyl alcohol;
• or polybutadiene acrylonitrile acrylic acid copolymer,
• at least one monomeric cross-linking agent containing at least one double bond and being selected from the group consisting of:
• ethylene glycol diacrylate, tetraethylene glucol diacrylate, neopentyl glycol diacrylate, tetrapropylene glycol diacrylate, trimethylolpropane triacrylate, ethylene glycol dimethyacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diomethacrylate, trimethylolpropane trimethacrylate, dicyclopentenyl oxyethyl methacrylate, divinyl benzene, 1,6-hexandiol diacrylate, tripropylene glycol diacrylate, diehyleneglycol divinyl ether,
• water, and
• at least one clay,
• down the inside of said drill string and out said at least one orifice,
• withdrawing said drill string from said wellbore,
• installing a float shoe having an upper seating surface on the lower end of a first section of well casing,
• assembling a casing string by sequentially attaching additional sections of casing to said first section of well casing and inserting the casing string farther into the wellbore,
• inserting a bottom plug into said casing string, said bottom plug having a longitudinal passage closed on an upper end by a rupturable diaphragm,
• pumping an additional amount of said drilling fluid containing a chemical initiator adapted to harden said drilling fluid into said casing string above said bottom plug, thereby moving said bottom plug downward in said casing string,
• inserting a closing plug into said casing string, said closing plug having circumferential wipers,
• moving said closing plug down said casing string above said closing plug so as to rupture said rupturable diaphragm and to substantially displace said drilling fluid from the inside of said casing string,
• whereby the drilling fluid remaining on the outside of the casing string cures into a cementitious material.