← Back to Patent Explorer
US4452638A Expired / Lapsed US ⏱️ 0.0 years remaining

Marker fluid composition for spotting cement in offshore wells

Assignee: Union Oil Company of California
•
Filing: 1983-04-28
•
Granted: 1984-06-05
•
Expires: 2003-04-28
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Cementing casing in an offshore well by displacing a drilling fluid with a settable cement slurry wherein there is injected into the annulus between the sidewall of the well and the casing ahead of the cement slurry a slug of a visually identifiable marker fluid containing cement, water, particulate carbon black, coal dust, and a surface active agent; visually observing when the fluid being displaced from the annulus changes from drilling fluid to marker fluid, and shutting in the well to allow the cement slurry to set.

Inventors

  • 👤 Julius P. Gallus

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 19:22
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/42; C04; C04B; C04B28/00; C04B28/02; E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/14; E21B47/00; E21B47/005

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 72 words
A marker fluid composition for use in positioning a cement slurry in the annulus between a borehole and casing in an offshore well comprising: (a) 100 parts by weight cement, (b) about 35 to 56 parts by weight water, (c) about 5 to 8 parts by weight particulate carbon black, (d) about 4 to 6.4 parts by weight coal dust, and (c) about 0.52 to 0.84 parts by weight surface active agent.
Claim 2
Dependent Claim 72 words
A marker fluid composition for use in positioning a cement slurry in the annulus between a borehole and casing in an offshore well comprising: (a) 100 parts by weight cement, (b) about 35 to 56 parts by weight water, (c) about 5 to 8 parts by weight particulate carbon black, (d) about 4 to 6.4 parts by weight coal dust, and (c) about 0.52 to 0.84 parts by weight surface active agent.
Claim 3
Dependent Claim 13 words
The composition of claim 1 wherein the cement is an oil well cement.
Claim 4
Dependent Claim 26 words
The composition of claim 2 wherein the oil well cement is selected from the group consisting of A.P.I. Class A, B, C, G or H cement.
Claim 5
Dependent Claim 29 words
The composition of claim 1 wherein the cement is selected from the group consisting of Portland cement, pozzolan cement, high alumina cement, lightweight cement, thixotropic cement and expanding cement.
Claim 6
Dependent Claim 20 words
The composition of claim 1 wherein the cement and part of the water required is added as a cement slurry.
Claim 7
Dependent Claim 36 words
The composition of claim 1 wherein the carbon black is selected from the group consisting of carbon black made by the oil furnace process, the acetylene black process, the lampblack process and the channel black process.
Claim 8
Dependent Claim 16 words
The composition of claim 1 wherein the carbon black is made by the channel black process.
Claim 9
Dependent Claim 21 words
The composition of claim 1 wherein the coal dust is selected from the group consisting of anthracite, bituminous and sub-bituminous coal.
Claim 10
Dependent Claim 13 words
The composition of claim 8 wherein the coal dust is anthracite coal dust.
Claim 11
Dependent Claim 24 words
The composition of claim 1 wherein the surface active agent is selected from the group consisting of anionic, nonionic and amphoteric surface active agents.

References Cited (Backward Citations)

US2010755A Cited
US2308176A Cited
US2609886A Cited
US3117146A Cited
US3376146A Cited
US3489219A Cited
US3730267A Cited
US4006031A Cited
US4043828A Cited
US4069870A Cited
US4114692A Cited
US4144077A Cited
US4200153A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-06-05 1987-12-05 1988-06-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-06-05 1991-12-05 1992-06-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-06-05 1995-12-05 1996-06-05 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag