Enhanced high-density ductile anti-channeling cement slurry for oil and gas well cementing

Abstract

The invention discloses a reinforced high-density tough anti-channeling cement paste for well cementation of an oil-gas well. Based on the weight of cement (100%), the reinforced high-density tough anti-channeling cement paste comprises the following components in percentage by weight: 22.5-24.0% of silica sand, 66.0-117.5% of iron ore powder, 8.9-11.9% of reinforcing agent, 10.0-12.5% of flexible anti-channeling agent, 1-1.25% of toughener, 2.0-2.5% of dispersing agent, 5.6-7.1% of fluid loss control agent, 2.0-2.5% of retarder, 0.2-0.25% of defoamer and 54.2-64% of water. The cement paste provided by the invention has favorable engineering properties, so that high-density set cement has the properties of high compression strength, low elasticity modulus and high tensile strength, and the mechanical properties of the set cement are effectively improved; and the cement paste can keep the integrity and the sealing property for oil-gas-water in a stratum for a long time, thereby effectively controlling secondary channeling.

Description

technical field

[0001] The invention relates to an enhanced high-density toughness anti-channeling cement slurry for oil and gas well cementing, which belongs to the field of petroleum drilling engineering. Background technique

[0002] Annulus channeling means that the fluid in the formation flows from the high-pressure layer to the low-pressure layer or the ground through the channeling channel (the cement sheath itself or the two interfaces of the annulus) under the action of the pressure difference, resulting in the mutual channeling of oil, gas, and water between the underground layers or Oil, gas and water are coming out of the wellhead. Annular channeling can be divided into the following two types: (1) annular channeling through the cement sheath itself; (2) annular channeling through the two interfaces.

[0003] The micro-annulus and micro-cracks in the annulus are the root causes of channeling. When the casing is subjected to high temperature and high pressure (s...

Examples

Embodiment 1

[0021] Weigh 500g G grade oil well cement, 330g iron ore powder, 120g silicon powder, 50g reinforcing agent, 50g flexible anti-channeling agent, 10g dispersant, 5g toughening agent, 30g fluid loss reducer, 10g retarder, 1g defoamer , 289g tap water. Dry mix iron ore powder, silicon powder, reinforcing agent, flexible anti-channeling agent, toughening agent and dispersant with cement first, then add fluid loss reducer, retarder and defoamer into tap water and mix evenly, press Prepare cement slurry according to GB / T19139-2012 standard.

Embodiment 2

[0023] Weigh 420g G grade oil well cement, 430g iron ore powder, 100g silicon powder, 50g reinforcing agent, 50g flexible anti-channeling agent, 10g dispersant, 5g toughening agent, 30g fluid loss reducer, 10g retarder, 1g defoamer , 269g tap water. Dry mix iron ore powder, silicon powder, reinforcing agent, flexible anti-channeling agent, toughening agent and dispersant with cement first, then add fluid loss reducer, retarder and defoamer into tap water and mix evenly, press Prepare cement slurry according to GB / T19139-2012 standard.

Embodiment 3

[0025] Weigh 450g G grade oil well cement, 400g iron ore powder, 110g silicon powder, 40g reinforcing agent, 50g flexible anti-channeling agent, 10g dispersant, 5g toughening agent, 25g fluid loss reducer, 10g retarder, 1g defoamer , 244g tap water. Dry mix iron ore powder, silicon powder, reinforcing agent, flexible anti-channeling agent, toughening agent and dispersant with cement first, then add fluid loss reducer, retarder and defoamer into tap water and mix evenly, press Prepare cement slurry according to GB / T19139-2012 standard.

technical field

[0001] The invention relates to an enhanced high-density toughness anti-channeling cement slurry for oil and gas well cementing, which belongs to the field of petroleum drilling engineering. Background technique

[0002] Annulus channeling means that the fluid in the formation flows from the high-pressure layer to the low-pressure layer or the ground through the channeling channel (the cement sheath itself or the two interfaces of the annulus) under the action of the pressure difference, resulting in the mutual channeling of oil, gas, and water between the underground layers or Oil, gas and water are coming out of the wellhead. Annular channeling can be divided into the following two types: (1) annular channeling through the cement sheath itself; (2) annular channeling through the two interfaces.

[0003] The micro-annulus and micro-cracks in the annulus are the root causes of channeling. When the casing is subjected to high temperature and high pressure (s...

Examples

Embodiment 1

[0021] Weigh 500g G grade oil well cement, 330g iron ore powder, 120g silicon powder, 50g reinforcing agent, 50g flexible anti-channeling agent, 10g dispersant, 5g toughening agent, 30g fluid loss reducer, 10g retarder, 1g defoamer , 289g tap water. Dry mix iron ore powder, silicon powder, reinforcing agent, flexible anti-channeling agent, toughening agent and dispersant with cement first, then add fluid loss reducer, retarder and defoamer into tap water and mix evenly, press Prepare cement slurry according to GB / T19139-2012 standard.

Embodiment 2

[0023] Weigh 420g G grade oil well cement, 430g iron ore powder, 100g silicon powder, 50g reinforcing agent, 50g flexible anti-channeling agent, 10g dispersant, 5g toughening agent, 30g fluid loss reducer, 10g retarder, 1g defoamer , 269g tap water. Dry mix iron ore powder, silicon powder, reinforcing agent, flexible anti-channeling agent, toughening agent and dispersant with cement first, then add fluid loss reducer, retarder and defoamer into tap water and mix evenly, press Prepare cement slurry according to GB / T19139-2012 standard.

Embodiment 3

[0025] Weigh 450g G grade oil well cement, 400g iron ore powder, 110g silicon powder, 40g reinforcing agent, 50g flexible anti-channeling agent, 10g dispersant, 5g toughening agent, 25g fluid loss reducer, 10g retarder, 1g defoamer , 244g tap water. Dry mix iron ore powder, silicon powder, reinforcing agent, flexible anti-channeling agent, toughening agent and dispersant with cement first, then add fluid loss reducer, retarder and defoamer into tap water and mix evenly, press Prepare cement slurry according to GB / T19139-2012 standard.

Images