Plugging solution precipitation time control

Patent · Tue May 01 04:00:00 EDT 1973

OSTI ID:5005618

Richardson, E A; Scheuerman, R F

A precipitate-forming solution is adapted to maintain its homogeneity and a selected degree of mobility through-out an exposure to a selected combination of time and temperature and then become relatively immobile due to the precipitation of a gelatinous metal hyroxide. The present precipitate-form solution comprises an aqueous solution of both a polyvalent-metal that forms a gelatinous metal hydroxide and a pH-increasing reactant that contains a mixture of nitrite ions and urea. This precipitate-forming solution is useful in numerous fluid diverting and plugging operations. It can be used in treating wells or boreholes (1) to plug portions of a subterranean reservoir from which, or into which, it is no longer desirable to inject fluids; (2) to plug off an intrusion of water into a gas drilled well borehole; (3) to improve the uniformity of the injection profile of a reservoir interval; (4) to pretreat the borehole of a well in which a casing is to be cemented to enhance the sealing effect of the cement bonds; or (5) to prevent or control a loss of fluid that is circulated within a well or borehole. (6 claims)

• Assignee: Shell Oil Co.
• Patent Number(s): US 3730272
• OSTI ID: 5005618
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ADDITIVES
AMBIENT TEMPERATURE
AMIDES
AQUEOUS SOLUTIONS
CARBONIC ACID DERIVATIVES
CONTROL
DISPERSIONS
ELEMENTS
INTERACTIONS
METALS
MIXTURES
NITRITES
NITROGEN COMPOUNDS
OIL WELLS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PLUGGING
PRECIPITATION
RESERVOIR ROCK
SEPARATION PROCESSES
SOLUTIONS
UREA
WELLS