CN105062437B - A kind of oil-in-water emulsified drilling fluid of anti-240 DEG C of high temperature - Google Patents

Abstract

The invention relates to an oil-in-water emulsified drilling fluid resistant to a high temperature of 240 DEG C, belonging to the technical field of drilling fluids for petroleum drilling. Its raw material composition includes 70 parts of water, 30 parts of base oil, 0.1 to 0.4 parts of caustic soda, 2.0 to 4.0 parts of tackifier, 4.0 to 6.0 parts of primary emulsifier, 1.0 to 3.0 parts of auxiliary emulsifier, and 2 to 5 parts of fluid loss reducer agent, 0.5 to 2.0 parts of high temperature stabilizer and 1.0 to 3.0 parts of flow regulator. The preparation method is as follows: first put water into a high-speed mixer at 10,000 rpm, and then put in the thickener, auxiliary emulsifier, main emulsifier, fluid loss reducer, high temperature stabilizer and flow pattern regulator in turn, and wait for all After the component raw materials are added and all mixed, stir at a high speed for another 60 minutes at normal temperature and pressure to complete the preparation. The invention has good emulsification stability, rock-carrying ability, dehydration wall-building property and lubricity under high-temperature conditions.

Description

An oil-in-water emulsified drilling fluid resistant to high temperature of 240°C

technical field

The invention relates to an oil-in-water emulsified drilling fluid resistant to a high temperature of 240 DEG C, belonging to the technical field of drilling fluids for petroleum drilling.

Background technique

Due to the low formation pressure, deep burial and high formation temperature in the buried hill structural belt of Nanpu Oilfield in the Bohai Bay area, drilling fluid leakage and reservoir damage are prone to occur. In order to discover new oil and gas reservoirs in a timely and accurate manner and develop oil and gas resources more effectively, more underbalanced drilling operations are implemented to maximize the discovery and protection of reservoirs. At present, the drilling fluid systems commonly used in low-pressure and leaky formations at home and abroad include gas drilling fluid, oil-based drilling fluid, oil-in-water drilling fluid, foam drilling fluid and micro-foam drilling fluid, etc., according to different drilling fluid systems The density range is different, among which the density range of gas is the smallest, followed by foam and microbubble, followed by oil-based and oil-in-water respectively. During the drilling process, because foam and micro-foam are sensitive to pressure, when drilling to a certain depth, the foam cannot reduce the density after the foam ruptures. At this stage, foam stability is a worldwide problem. At the same time, the foam and micro-foam drilling fluid systems will affect the electrical measurement and data transmission due to their incoherent systems. However, air, air and foam drilling also need to be equipped with special equipment on site, so there are certain limitations in practicability.

Relatively speaking, oil-based drilling fluids and oil-in-water drilling fluids are relatively widely used. Due to oil-based drilling fluids polluting the environment, the cost pressure of subsequent drilling cuttings is high and cost problems (especially for easy Lost formations), there are certain limitations. Therefore, comprehensively considered, the oil-in-water drilling fluid system has stable performance, strong ability to stabilize the wellbore wall, and a lower density than ordinary water-based drilling fluids. Good reservoir protection performance and other characteristics, at the same time, it has less environmental pollution, relatively easy follow-up cuttings treatment, and lower cost than oil-based drilling fluid, so it is suitable for underbalanced drilling operations.

In 1992, Huabei Oilfield drilled the first medium-curvature-radius horizontal well on land in my country—Well Renping 1, with water-in-diesel drilling fluid, which has a temperature resistance of 120°C; The liquid system has been applied in the underbalanced drilling of Well G2 in Dagang Oilfield, and its temperature resistance can reach 150°C. The crude oil-in-brine drilling fluid system developed by Shengli Oilfield was successfully applied in the first medium-curvature horizontal well in Jianghan Oilfield, with a temperature resistance of 100°C. Daqing Oilfield used the water-in-diesel drilling fluid system for underbalanced drilling for the first time in 2000. It was successfully applied in the third underbalanced section of Well Songshen 101, and the temperature resistance reached 150°C. In 2008, Daqing Oilfield developed an oil-in-water drilling fluid with a density of 0.90g/cm ³ and a temperature resistance of nearly 200°C. The field application well temperature is around 180°C. From 2009 to 2013, Jidong Oilfield implemented underbalanced drilling in the Nanpu buried hill, using a high-temperature resistant oil-in-water drilling fluid system, and the applied well temperature was around 150-200 °C. Although the oil-in-water drilling fluid has been successfully applied in China, there is no report on the high-temperature oil-in-water drilling fluid system above 240 °C, and the formation temperature encountered in the buried hill reservoir of Jidong Oilfield is getting higher and higher. High, the buried hill reservoir temperature in block PG2 is above 200°C. Although the temperature resistance of the oil-in-water drilling fluid system is gradually improving, for the exploration and development of high-temperature deep well reservoirs in buried hills like Nanpu Oilfield, oil-in-water drilling fluids that can withstand high temperatures of 240 °C are required. Oil drilling fluid can not meet its requirements.

Contents of the invention

The purpose of the present invention is to provide an oil-in-water drilling fluid with good emulsification stability, rock-carrying ability, dehydration and wall-building properties and lubrication under high temperature conditions. It is an oil-in-water emulsified drilling fluid that can resist high temperature of 240℃ and can satisfy the exploration and development of high-temperature deep well fractured reservoirs and low-pressure depleted reservoirs.

The present invention achieves the above-mentioned purpose through the following technical solutions

An oil-in-water emulsified drilling fluid resistant to 240°C high temperature is characterized in that it is made of the following raw materials in parts by weight:

70 parts of water,

30 parts of 5# white oil,

Caustic soda 0.1～0.4 parts,

Tackifier 2.0～4.0 parts,

Main emulsifier 4.0～6.0 parts,

Co-emulsifier 1.0～3.0 parts,

2 to 5 parts of fluid loss reducer,

High temperature stabilizer 0.5～2.0 parts,

Flow regulator 1.0～3.0 parts;

The preparation method of the oil-in-water emulsified drilling fluid resistant to 240°C high temperature is as follows: first put water into a high-speed mixer at 10,000 rpm, then put in a viscosifier and stir for 20 minutes, then put in an auxiliary emulsifier and stir for 2 minutes, and then Then put in the main emulsifier and stir for 30 minutes, then put in the fluid loss reducer and high temperature stabilizer and stir for 20 minutes, and finally put in the flow regulator and stir for 20 minutes; Stir at high speed for another 60 minutes to complete the preparation.

The optimal weight ratio of the raw materials of the 240°C high temperature oil-in-water emulsified drilling fluid is:

70 parts of water,

30 parts of 5# white oil,

0.2 parts of caustic soda,

3.0 parts of tackifier,

5.0 parts of main emulsifier,

Co-emulsifier 1.0 part,

3 parts of fluid loss reducer,

1 part high temperature stabilizer,

Flow regulator 1.5 parts.

The tackifier is prepared by mixing attapulgite clay and sepiolite, and the ratio of attapulgite clay to sepiolite is 3-4:1-2.

The main emulsifier is mixed and stirred by fatty alcohol polyoxyethylene ether sulfosuccinic monoester disodium, sodium rosinate, fatty alcohol polyoxyethylene ether AEO9 at a temperature of 80°C and a high-speed stirring of 10,000 rpm for 20 minutes. The ratio of fatty alcohol polyoxyethylene ether sulfosuccinic monoester disodium: abietic acid sodium: fatty alcohol polyoxyethylene ether AEO9 is 1~3:2~3:1~2.

The co-emulsifier is prepared by mixing and stirring calcium dodecylbenzenesulfonate, vegetable oleic acid, and 5# white oil for 20 minutes at a temperature of 80°C and at a high speed of 10,000 rpm. Dodecylbenzenesulfonate The ratio of calcium acid: vegetable oleic acid: 5# white oil is 3~5: 2~4: 5~7.

The fluid loss reducer is prepared by mixing water-absorbing resin and sulfomethylphenol-formaldehyde resin, drying at 105°C, and grinding them into 200-mesh powder. The ratio of water-absorbing resin:sulfonated phenol-formaldehyde resin is 0.5～2:3 ~5.

The high-temperature stabilizer is one of nano-calcium carbonate, nano-silicon dioxide, and nano-montmorillonite.

The flow regulator is prepared by mixing nano-montmorillonite and lithium-magnesium silicate, and the ratio of nano-montmorillonite:lithium-magnesium silicate is 0.5-2.0:5-8.

Compared with the prior art, the present invention has the beneficial effect of

1. The temperature resistance can reach 240 ℃, stable performance, good fluidity, small filtration loss, strong ability to stabilize the well wall, and meet the needs of underbalanced drilling in high-temperature deep wells;

2. The density is lower than that of ordinary water-based drilling fluid, and the damage to the reservoir is minimal during underbalanced drilling, which is conducive to liberating oil and gas layers and increasing the productivity of oil and gas wells;

3. Helps prevent lost circulation and increase ROP without affecting electrical and nuclear magnetic logging;

4. Compared with foam and aerated drilling fluid systems, it does not need to be equipped with complex equipment during use, and its performance is easy to monitor, control and adjust;

5. The lubricating effect is good, which can reduce the damage to the mud pump;

6. Compared with pure oil-based drilling fluid, the cost is lower, the damage to rubber parts is small, and the environmental pollution is small.

detailed description

The 240°C high-temperature oil-in-water emulsified drilling fluid is described in detail below through specific examples:

Example 1:

First determine the weight of each part according to the preparation requirements, and then weigh the raw materials according to the following parts by weight.

70 parts of water;

30 parts of 5# white oil;

0.2 parts of caustic soda;

3.0 parts of tackifiers are prepared by mixing attapulgite clay and sepiolite, and the ratio of attapulgite clay to sepiolite is 3.5:1.5;

5.0 parts of the main emulsifier, made of fatty alcohol polyoxyethylene ether sulfosuccinic acid monoester disodium, rosin acid sodium, fatty alcohol polyoxyethylene ether AEO9 at a temperature of 80 ° C and 10,000 rpm under high-speed stirring for 20 Prepared in minutes, the ratio of fatty alcohol polyoxyethylene ether sulfosuccinic monoester disodium: sodium rosinate: fatty alcohol polyoxyethylene ether AEO9 is 2: 2.5: 1.5;

1.0 parts of co-emulsifier, prepared by mixing calcium dodecylbenzenesulfonate, vegetable oleic acid, and 5# white oil at a temperature of 80°C and stirring at a high speed of 10,000 rpm for 20 minutes. Dodecylbenzenesulfonate The ratio of calcium acid: vegetable oleic acid: 5# white oil is 3.5: 3: 6;

3 parts of fluid loss reducer, made by mixing water-absorbent resin and sulfomethylphenol-formaldehyde resin, drying at 105°C, and grinding them into 200-mesh powder. The ratio of water-absorbent resin:sulfonated phenol-formaldehyde resin is 1:4;

1 part of high temperature stabilizer, which is nano silicon dioxide;

1.5 parts of flow regulator, made by mixing nano-montmorillonite and lithium magnesium silicate, the ratio of nano-montmorillonite to lithium magnesium silicate is 1:7;

The preparation method of the oil-in-water emulsified drilling fluid resistant to 240°C high temperature is as follows: first put water into a high-speed mixer at 10,000 rpm, then put in a viscosifier and stir for 20 minutes, then put in an auxiliary emulsifier and stir for 2 minutes, and then Then put in the main emulsifier and stir for 30 minutes, then put in the fluid loss reducer and high temperature stabilizer and stir for 20 minutes, and finally put in the flow regulator and stir for 20 minutes; Stir at high speed for another 60 minutes to complete the preparation.

Example 2:

First determine the weight of each part according to the preparation requirements, and then weigh the raw materials according to the following parts by weight.

70 parts of water;

30 parts of 5# white oil;

0.1 parts of caustic soda;

2.0 parts of tackifier, made by mixing attapulgite clay and sepiolite, the ratio of attapulgite clay to sepiolite is 3:1;

4.0 parts of the main emulsifier, made of fatty alcohol polyoxyethylene ether sulfosuccinic acid monoester disodium, rosin acid sodium, fatty alcohol polyoxyethylene ether AEO9 at a temperature of 80 ° C and 10,000 rpm under high-speed stirring for 20 Prepared in minutes, the ratio of fatty alcohol polyoxyethylene ether sulfosuccinic monoester disodium: sodium rosinate: fatty alcohol polyoxyethylene ether AEO9 is 1: 2: 1;

1.0 parts of co-emulsifier, prepared by mixing calcium dodecylbenzenesulfonate, vegetable oleic acid, and 5# white oil at a temperature of 80°C and stirring at a high speed of 10,000 rpm for 20 minutes. Dodecylbenzenesulfonate The ratio of calcium acid: vegetable oleic acid: 5# white oil is 3: 2: 5;

2 parts of fluid loss reducer, made by mixing water-absorbing resin and sulfomethylphenol-formaldehyde resin, drying at 105°C, and grinding them into 200-mesh powder. The ratio of water-absorbing resin:sulfonated phenol-formaldehyde resin is 0.5:3;

0.5 part of high-temperature stabilizer is nano silicon dioxide;

1.0 parts of flow regulator, made by mixing nano-montmorillonite and lithium magnesium silicate, the ratio of nano-montmorillonite and lithium magnesium silicate is 0.5:5;

The preparation method of the oil-in-water emulsified drilling fluid resistant to 240°C high temperature is as follows: first put water into a high-speed mixer at 10,000 rpm, then put in a viscosifier and stir for 20 minutes, then put in an auxiliary emulsifier and stir for 2 minutes, and then Then put in the main emulsifier and stir for 30 minutes, then put in the fluid loss reducer and high temperature stabilizer and stir for 20 minutes, and finally put in the flow regulator and stir for 20 minutes; Stir at high speed for another 60 minutes to complete the preparation.

Example 3:

First determine the weight of each part according to the preparation requirements, and then weigh the raw materials according to the following parts by weight.

70 parts of water;

30 parts of 5# white oil;

0.4 parts of caustic soda;

4.0 parts of tackifier, made by mixing attapulgite clay and sepiolite, the ratio of attapulgite clay to sepiolite is 4:2;

6.0 parts of the main emulsifier, made of fatty alcohol polyoxyethylene ether sulfosuccinic acid monoester disodium, rosin acid sodium, fatty alcohol polyoxyethylene ether AEO9 at a temperature of 80 ° C and 10,000 rpm under high-speed stirring for 20 Prepared in minutes, the ratio of fatty alcohol polyoxyethylene ether sulfosuccinate disodium: sodium abietate: fatty alcohol polyoxyethylene ether AEO9 is 3:3:2;

3.0 parts of co-emulsifier, prepared by mixing calcium dodecylbenzenesulfonate, vegetable oleic acid, and 5# white oil at a temperature of 80°C and stirring at a high speed of 10,000 rpm for 20 minutes. Dodecylbenzenesulfonate The ratio of calcium acid: vegetable oleic acid: 5# white oil is 5:4:7;

5.0 parts of fluid loss reducer, made by mixing water-absorbing resin and sulfomethylphenol-formaldehyde resin, drying at 105°C, and grinding them into 200-mesh powder. The ratio of water-absorbing resin:sulfonated phenol-formaldehyde resin is 2:5;

2.0 parts of high-temperature stabilizers are nano silicon dioxide;

3.0 parts of flow regulator, made by mixing nano-montmorillonite and lithium magnesium silicate, the ratio of nano-montmorillonite and lithium magnesium silicate is 2:8;

The preparation method of the oil-in-water emulsified drilling fluid resistant to 240°C high temperature is as follows: first put water into a high-speed mixer at 10,000 rpm, then put in a viscosifier and stir for 20 minutes, then put in an auxiliary emulsifier and stir for 2 minutes, and then Then put in the main emulsifier and stir for 30 minutes, then put in the fluid loss reducer and high temperature stabilizer and stir for 20 minutes, and finally put in the flow regulator and stir for 20 minutes; Stir at high speed for another 60 minutes to complete the preparation.

Above each embodiment prepares the drilling fluid of the present invention of 400ml, by 240 ℃ of thermal rolling aging 16 hours, the performance test data of the drilling fluid of the present invention prepared by each embodiment is as follows table:

Among the above-mentioned examples, Example 1 is the best example of the present invention, and no oil is precipitated after aging at 240°C for 16 hours, indicating that the emulsion has strong thermal stability, and at the same time, the drilling fluid prepared by the present invention has better The rheology and water loss wall-building properties can effectively carry rocks and form dense mud cakes to stabilize the well wall, meeting the exploration and development of high-temperature deep well fractured reservoirs and low-pressure depleted reservoirs.

The above is only the specific implementation of the invention, and the above illustrations do not limit the essence of the present invention. Those of ordinary skill in the art can modify or deform the above specific implementation after reading this specification, without depart from the spirit and scope of the invention.

Claims (1)

1. An oil-in-water emulsified drilling fluid resistant to 240°C high temperature, which is made of the following raw materials in parts by weight: 70 parts of water, 30 parts of 5# white oil, 0.2 parts of caustic soda, 3.0 parts of tackifier, 5.0 parts of main emulsifier, Co-emulsifier 1.0 part, 3 parts of fluid loss reducer, 1 part high temperature stabilizer, 1.5 parts of flow regulator; It is characterized by: The main emulsifier is mixed and stirred by fatty alcohol polyoxyethylene ether sulfosuccinic monoester disodium, sodium rosinate, fatty alcohol polyoxyethylene ether AEO9 at a temperature of 80°C and a high-speed stirring of 10,000 rpm for 20 minutes. Prepared in minutes, the ratio of fatty alcohol polyoxyethylene ether sulfosuccinic monoester disodium: abietic acid sodium: fatty alcohol polyoxyethylene ether AEO9 is 1～3: 2～3: 1～2; The co-emulsifier is prepared by mixing and stirring calcium dodecylbenzenesulfonate, vegetable oleic acid, and 5# white oil for 20 minutes at a temperature of 80°C and at a high speed of 10,000 rpm. Dodecylbenzenesulfonate The ratio of calcium acid: vegetable oleic acid: 5# white oil is 3～5: 2～4: 5～7; The high-temperature stabilizer is one of nano-calcium carbonate, nano-silicon dioxide, and nano-montmorillonite; The flow regulator is prepared by mixing nano-montmorillonite and lithium-magnesium silicate, and the ratio of nano-montmorillonite: lithium-magnesium silicate is 0.5-2.0:5-8; The preparation method of the oil-in-water emulsified drilling fluid resistant to 240°C high temperature is as follows: first put water into a high-speed mixer at 10,000 rpm, then put in a thickener and stir for 20 minutes, then put in an auxiliary emulsifier and stir for 2 minutes, and then Then put in the main emulsifier and stir for 30 minutes, then put in the fluid loss reducer and high temperature stabilizer and stir for 20 minutes, and finally put in the flow regulator and stir for 20 minutes; Stir at high speed for another 60 minutes to complete the preparation.