# US 2009/0260545 A1 · Well Cement Formulations for Increased Drilling Hardness > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260545 A1 - Document ID: US20090260545A1 - Status: Published application - Kind: A1 - Application number: 11/992,184 - Filed: 2006-09-15 - Published: 2009-10-22 - Earliest claimed: 2005-09-16 - Assignees: Saudi Arabian Oil Company - Inventors: Abdullah Saleh Hussain Al-Bari Al-Yami; Scott Steven Jennings; Abdulkarin I. Khafaji; Ahmed Saleh Al-Humaidi - Web page: https://patentgrep.com/patent/US20090260545A1 ## CPC - C04B 28/02: containing hydraulic cements other than calcium sulfates - C09K 8/426: {for plugging} - C09K 8/473: Density reducing additives, e.g. for obtaining foamed cement compositions - Y02W 30/91: Use of waste materials as fillers for mortars or concrete - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT ## Abstract A well cement composition for plugging a bore at the location for initiating sidetracking to bore a lateral well is formulated as a slurry of hydraulic cement that contains at least two, but preferably all three of the following additives: (1) a source of silicon dioxide, (2) fracturing proppants and (3) an expansion compound selected from the group consisting of 1%-5% crystalline silica and 60%-99% MgO or CaO, and their mixtures. ## Claims ### Claim 1 A well cement composition containing hydraulic cement that includes the following additives to increase the hardness of the cured composition: a. silicon dioxide source; b. fracturing proppant; and c. an expansion compound selected from the group consisting of 1%-5% crystalline silica and 60-99% MgO or CaO, and mixtures thereof. ### Claim 2 (depends on 1) The cement composition of claim 1 in which the additives are present in the following percentages by weight, based on the weight of the cement: a. silicon dioxide source, from 10% to 250%; b. fracturing proppants, from 10% to 400%; and c. expansion compounds, from 0.5% to 10%. ### Claim 3 (depends on 2) The cement composition of claim 2, having the following percentage of additives, by weight, based on the weight of the hydraulic cement: a. 100% of silicon dioxide source; b. 100% of fracturing proppant; and c. 1% of an expansion compound. ### Claim 4 (depends on 1) The cement composition of claim 1 that also includes secondary additives selected from the group consisting of anti-foaming agents, latex and latex stabilizers, friction-reducing compounds, setting-time retardant compounds, anti-settling compounds, and combinations thereof. ### Claim 5 (depends on 4) The cement composition of claim 4 having the following formulation, by weight, based on the weight of the dry hydraulic cement present: hydraulic cement water: 18%-200%, silicon dioxide source: 10%-250%, hematite (iron oxide) or manganese tetraoxide: 0%-200%, fiber: 0%-200%, fluid loss additives: 0%-2%, retarder additives: 0%-10%, friction reducer dispersant additive: 0%-2.5%, latex additive: 0%-50%, latex stabilizer additive: 0%-4%, anti-settling additive: 0%-2%, accelerator additive: 0%-5%, anti-foaming additive: 0%-0.1%, and fumed silica: −0%-50%. ### Claim 6 A cement plug set in a well bore at a predetermined drilling site for the initiation of a lateral well bore, the cement plug formed from a composition that comprises hydraulic cement and at least two of the following additives: a. a silicon dioxide source; b. a fracturing proppant; c. an expansion compound selected from the group consisting of 1% to 10% crystalline silica and 60-99% MgO or CaO, and mixtures thereof. ### Claim 7 (depends on 6) The well cement plug of claim 6 in which the silicon dioxide source is silica flour, the fracturing proppant is ceramic, and the expansion compound includes MgO. ### Claim 8 A well cement composition containing hydraulic cement and formulated for use as a plug at a predetermined position in a well bore passing through a rock formation, the cured cement composition having a rate of penetration (ROP) that is approximately equal to the ROP of the surrounding formation, the composition including the following additives: a. silicon dioxide source; b. fracturing proppant; and c. an expansion compound selected from the group consisting of from 1% to 10% crystalline silica and 60-99% MgO or CaO, and mixtures thereof. ### Claim 9 A method of formulating a well cement composition containing hydraulic cement for use in forming a cured cement plug at a predetermined position in a well bore to provide a rate of penetration (ROP) value for the cement plug that is comparable to the ROP of the adjacent rock formation, the method comprising the steps of: a. determining and recording the ROP value for the rock formation at the predetermined well depth; b. comparing the value of the ROP of the rock formation from (a) to a table of ROP test values obtained by testing cured cement compositions that included the following additives to increase the harness of the cured cement: i. a silicon dioxide source; ii. a fracturing proppant; and iii. an expansion compound selected from the group consisting of from 1% to 10% crystalline silica and 60-99% MgO or CaO, and mixtures thereof; c. identifying an ROP test value for a cement composition that is the same as, greater than, or if neither is present in the table, the closest lesser value to the ROP of the rock formation that is to be drilled; and d. selecting and preparing a well cement composition corresponding to the ROP test value identified in step (c). ### Claim 10 (depends on 9) The method of claim 9 in which the ROP value for the rock formation is determined by drilling a core sample from the same or a comparable formation. ### Claim 11 (depends on 9) The method of claim 9 in which the value of the ROP for the rock formation is entered in a programmed processor of a general purpose computer for comparison to a plurality of ROP values for well cement samples stored in the memory of the computer, and one or more compositions of well cements are displayed. ### Claim 12 (depends on 1) A method of preparing the well cement composition of claim 1 comprising the steps: a. mixing dry hydraulic cement with the source of silicon dioxide and the expansion additive, if present; b. mixing all of the other additives present, with the exception of the proppant, with water; c. adding the dry mixture of step (a) to the aqueous composition of step (b); and d. adding the proppant, if present, to the composition of step (c) to form a pumpable well cement slurry.