A grouting technology for the disposal of abandoned oil and gas pipelines

Pipeline grouting is a necessary measure to dispose abandoned pipelines safely and environmentally. It is particularly important to carry out experimental tests on grouting materials, compare key grouting equipments and test grouting methods on site, in order to solve grouting problems of abandoned oil and gas pipelines under different environmental conditions. The following research results were obtained. First, the grout materials mainly composed of pure cement, compounds of cement-fly ash or cement-clay or cement silt are cheap, convenient to access and environmentally friendly, and they can satisfy the requirements of pipeline grouting under different environmental conditions by adding different additives. Second, it is appropriate to apply the reciprocating pump to the grouting of oil and gas pipelines, and grout materials can be stirred by means of paddle, propeller or turbine agitator according to the requirements. Third, pure pressure grouting method can realize the one-trip short distance grouting, and vacuum assisted pressure grouting method can realize long distance grouting. And fourth, for the long-distance fast grouting of oil and gas pipelines, it is appropriate to adopt multiple pumps and mobile grout pool and control the strength after the solidification, concretion rate and total injecting volume to ensure the ultimate grouting effect.