NOVEL WEIGHTED ELASTOMER SYSTEMS FOR USE IN CEMENT, SPACER AND DRILLING FLUIDS
A drilling fluid, spacer fluid and cementing compositions for use in subterranean wells are disclosed along with methods for making using same, where the compositions include a particulate weighted elastomeric composition system including at least one higher density weighting agent and at least one elastomer, where the higher density weighting agents have a density of at least 5.0 g/cm 3 and conventional weighting agents, to produce compositions having a desired high density, while retaining other fluid properties such as pumpability, gas tight sealing, low tendency to segregate, and reduced high temperature cement strength retrogression.
1 . A cement composition comprising:
water,
a hydraulic cement, and
a weighted elastomer system including:
at least one higher density weighting agent and
at least one elastomer,
where the weighting agent has a density of at least 5.0 g/cm 3 and
where the weighted elastomer system increases a density of the composition, while maintaining other properties including at least pumpability, gas tight sealing, low tendency to segregate, and/or reduced high temperature cement strength retrogression.
2 . The composition of claim 1 , further comprising:
a gelling agent including oxides of antimony, zinc oxide, barium oxide, barium sulfate, barium carbonate, iron oxide, hematite, other irons ores and mixtures thereof,
a dispersant, and/or
a fluid loss control additive.
3 . The composition of claim 1 , the weighted elastomer system further includes:
a secondary weighting agent.
4 . The composition of claim 1 , the weighted elastomer system further includes:
a crosslinking agent,
a coupling agent, or
a mixture of a crosslinking agent and a coupling agent.
5 . The composition of claim 1 , the weighted elastomer system comprises a powder, a shot, or mixtures and combinations thereof.
6 . The composition of claim 1 , the composition has a relatively low plastic viscosity, a relatively low yield point, a relatively faster cure, a relatively higher cure strength after 6 hours of curing and relatively higher final cure strength relative to a cement composition having a weight equivalent of a hematite weighting agent.
7 . A cementitious composition comprising:
a cement,
a weighted elastomer system including:
at least one higher density weighting agent and
at least one elastomer,
water,
where the weighted elastomer system is present in an amount between about 0.5% by weight of the composition to about 50% by weight of the composition and where the higher weighting agent has a density of at least 5.0 g/cm 3 .
8 . The composition of claim 7 , wherein a ratio of the weighting agents and the elastomers is between about 9:1 and about 1:9.
9 . The composition of claim 7 , wherein the weighted elastomer system further includes:
a secondary weighting agent.
10 . The composition of claim 7 , wherein the weighted elastomer system further includes:
a crosslinking agent,
a coupling agent, or
a mixture of a crosslinking agent and a coupling agent.
11 . The composition of claim 1 , wherein the weighted elastomer system comprises a powder, a shot, or mixtures and combinations thereof.
12 . The composition of claim 1 , further comprising:
a gelling agent including oxides of antimony, zinc oxide, barium oxide, barium sulfate, barium carbonate, iron oxide, hematite, other irons ores and mixtures thereof;
a dispersing agent; a gelling agent; and/or
a fluid loss control additive.
13 . A method of cementing in an annulus between a well casing and a borehole of this invention comprising the step of:
placing in an annulus a cementitious composition, where the composition comprises:
water,
a hydraulic cement; and
a weighted elastomer system including:
at least one weighting agent and
at least one elastomer,
where the higher density weighting agents have a density of at least 5.0 g/cm 3 and where the weighted elastomer system increases the density of the composition, while maintaining other properties including at least pumpability, gas tight sealing, low tendency to segregate, and/or reduced high temperature cement strength retrogression.
14 . The method of claim 13 , further comprising the step of:
allowing the cement to set in place.
15 . The method of claim 13 , further comprising the step of:
a gelling agent including oxides of antimony, zinc oxide, barium oxide, barium sulfate, other irons ores or mixtures and combinations thereof,
a dispersing agent; and/or
a fluid loss control additive.
16 . The method of claim 13 , wherein a ratio of the weighting agents and the elastomers is between about 9:1 and about 1:9.
17 . The method of claim 1 , the weighted elastomer system further includes:
a secondary weighting agent.
18 . The method of claim 1 , wherein the weighted elastomer system further includes:
a crosslinking agent,
a coupling agent, or
a mixture of a crosslinking agent and a coupling agent.
19 . The method of claim 1 , wherein the weighted elastomer system comprises a powder, a shot, or mixtures and combinations thereof.
20 . A drilling fluid composition comprising:
a base fluid, and
a weighted elastomer system including at least one higher density weighting agent and at least one elastomer, where the higher density weighting agents have a density of at least 5.0 g/cm 3 ,
where the weighted elastomer system increases the density of the composition while maintaining other properties including at least pumpability, and/or low tendency to segregate.
21 . The composition of claim 20 , wherein a ratio of the higher density weighting agents and the elastomers is between about 9:1 and about 1:9.
22 . The composition of claim 20 , wherein the weighted elastomer system further includes a secondary weighting agent.
23 . The composition of claim 20 , wherein the weighted elastomer system further includes a crosslinking agent, a coupling agent, or a mixture of a crosslinking agent and a coupling agent.
24 . The composition of claim 20 , wherein the weighted elastomer system comprises a powder, a shot, or mixtures and combinations thereof.
25 . A methods for drilling a subterranean well comprising the steps:
circulating a drilling fluid, while drilling a borehole, where the drilling fluid includes a base fluid and an effective amount of a weighted elastomer system including at least one higher density weighting agent and at least one elastomer, where the higher density weighting agents have a density of at least 5.0 g/cm 3 in a bore hole, where the amount is effective to increase the column weight of the fluid to a desired pressure and where the drilling fluid has improved properties relative to a drilling fluid having a weight equivalent amount of a hematite weighting agent.
26 . A spacer fluid composition comprising:
a base fluid and
an effective amount of a weighted elastomer system including at least one higher density weighting agent and at least one elastomer,
where the higher density weighting agents have a density of at least 5.0 g/cm 3 , and
where the amount is sufficient to impart a desired high bulk density to the composition.
27 . A methods for changing fluids in a subterranean well comprising the steps of:
displacing a first fluid in the well with a spacer fluid, and
displacing the spacer fluid in the well with a second fluid,
where the first fluid and spacer fluid are incapable and the spacer fluid and the second fluid are incompatible and the spacer fluid includes a base fluid and an effective amount of a weighted elastomer system including at least one higher density weighting agent and at least one elastomer, where the higher density weighting agents have a density of at least 5.0 g/cm 3 .