阅读说明：本技术 一种钻进页岩用抗高温高密度油基钻井液及其配制方法 (High-temperature-resistant high-density oil-based drilling fluid for drilling shale and preparation method thereof ) 是由 周研 蒲晓林 邵旭佳 冷文龙 于 2019-10-16 设计创作，主要内容包括：本发明公开了一种钻进页岩用抗高温高密度油基钻井液及其配制方法,由以下组分组成：0#柴油240份、主乳化剂2～4份、辅乳化剂1.5～2.5份、降滤失剂2～4份、有机土1～1.5份、提切剂2～4份、润湿剂1～2份、25%氯化钙水溶液60份、碱度调节剂2份、重晶石粉0～783份,本发明的抗高温高密度油基钻井液可用于钻进页岩地层,油水比为8：2,密度为2.2g/cm<Sup>3</Sup>,抗温180℃,钻井液流变性受温度影响变化较小,性能稳定,使用范围广。该钻井液性能稳定,破乳电压高,且高温高密度条件下钻井液流变性容易控制,高温情况下钻井液黏度变化不大,解决了油基钻井液使用沥青类降滤失剂高温增黏的问题。(The invention discloses a high-temperature-resistant high-density oil-based drilling fluid for drilling shale and a preparation method thereof, wherein the drilling fluid comprises the following components: 240 parts of 0# diesel oil, 2-4 parts of a main emulsifier, 1.5-2.5 parts of an auxiliary emulsifier, 2-4 parts of a filtrate reducer, 1-1.5 parts of organic soil, 2-4 parts of a shear improver, 1-2 parts of a wetting agent, 60 parts of a 25% calcium chloride aqueous solution, 2 parts of an alkalinity regulator and 0-783 parts of barite powder, wherein the high-temperature resistant high-density oil-based drilling fluid can be used for drilling into a shale stratum, and the oil-water ratio is 8: 2, density of 2.2g/cm 3 The drilling fluid resists the temperature of 180 ℃, the rheological property of the drilling fluid is less influenced by the temperature, the performance is stable, and the application range is wide. The drilling fluid has stable performance and high demulsification voltage, the rheological property of the drilling fluid is easy to control under the conditions of high temperature and high density, the viscosity of the drilling fluid is not changed greatly under the high temperature condition, and the problem of high-temperature viscosity increase of the asphalt filtrate reducer used in the oil-based drilling fluid is solved.)

1. The high-temperature-resistant high-density oil-based drilling fluid for drilling shale is characterized by comprising the following components:

240 portions of 0# diesel oil

2-4 parts of main emulsifier

1.5-2.5 parts of auxiliary emulsifier

2-4 parts of filtrate reducer

1-1.5 parts of organic soil

2-4 parts of lifting and cutting agent

1-2 parts of wetting agent

60 parts of 25% calcium chloride aqueous solution

Alkalinity regulator 2 parts

And 0-783 parts of barite powder.

2. the high temperature resistant high density oil-based drilling fluid for drilling shale of claim 1, wherein: the fluid loss agent is prepared by reacting long-chain acrylate and acrylamide in a mass ratio of 1:3 for 6 hours at 70 ℃.

3. The preparation method of the high-temperature-resistant high-density oil-based drilling fluid for drilling the shale according to any one of claims 1-2, wherein the method comprises the following steps:

S1, taking materials: firstly, respectively weighing 2-4 parts of a main emulsifier, 1.5-2.5 parts of an auxiliary emulsifier, 2-4 parts of a cutting agent and 1-2 parts of a wetting agent, and weighing 240 parts of 0# diesel oil and 1-1.5 parts of organic soil;

S2, stirring: adding 240 parts of No. 0 diesel oil into a goblet, adding 2-4 parts of a main emulsifier, stirring for 5 minutes at a stirring speed of 10000 rpm, adding 1.5-2.5 parts of an auxiliary emulsifier at the same rotation speed, stirring for 5 minutes, adding 2-4 parts of a shear-improving agent at the same stirring speed, stirring for 5 minutes, adding 1-2 parts of a wetting agent, stirring for 10 minutes, adding 1-1.5 parts of organic soil under the stirring condition, stirring for 10 minutes, slowly adding 60 parts of a 25% calcium chloride aqueous solution, stirring for 10 minutes, sequentially adding 2-4 parts of a filtrate reducer and 2 parts of an alkalinity regulator, stirring for 20 minutes, adding 0-783 parts of barite powder, and stirring for 30 minutes at a stirring speed of 10000 rpm to prepare the high-temperature-resistant high-density oil-based drilling fluid.

4. The method for preparing the high-temperature-resistant high-density oil-based drilling fluid for drilling shale according to claim 3, wherein the method comprises the following steps:

s1, taking materials: firstly, respectively weighing 3 parts of a main emulsifier, 1.5 parts of an auxiliary emulsifier, 3 parts of a cutting agent and 2 parts of a wetting agent, and weighing 240 parts of 0# diesel oil and 1.5 parts of organic soil;

S2, stirring: adding 240 parts of 0# diesel oil into a goblet, adding 3 parts of main emulsifier, stirring for 5 minutes at a stirring speed of 10000 rpm, adding 1.5 parts of auxiliary emulsifier at the same rotating speed, stirring for 5 minutes, adding 3 parts of cutting agent at the same stirring speed, stirring for 5 minutes, adding 2 parts of wetting agent, stirring for 10 minutes, adding 1.5 parts of organic soil under the stirring condition, stirring for 10 minutes, slowly adding 60 parts of 25% calcium chloride aqueous solution, stirring for 10 minutes, sequentially adding 3 parts of filtrate reducer, 2 parts of alkalinity regulator, stirring for 20 minutes, adding 783 parts of barite powder, stirring for 30 minutes at a stirring speed of 10000 rpm, and thus obtaining the high-temperature-resistant high-density oil-based drilling fluid.

Technical Field

The invention relates to the technical field of petroleum, natural gas and shale gas drilling, in particular to a high-temperature-resistant high-density oil-based drilling fluid for drilling shale and a preparation method thereof.

background

as society develops, the demand for primary energy consumption increases, where the demand for oil and gas will increase from the current 7.2 to 11.5 million tons oil equivalent, rising from 24 to 31% by weight. According to statistics, the petroleum reserves of about 85 multiplied by 108t are not discovered in China so far, and 73 percent of the petroleum reserves are buried in the deep layer, so that the deep oil and gas resource exploration and development is the key for improving the comprehensive national strength of China and the oil and gas exploration and development benefits of various petroleum companies.

The drilling fluid is used as 'blood' of drilling engineering, plays a vital role in the whole drilling process, and the requirements on the performances of the drilling fluid are higher and higher due to the improvement of the drilling process technology, the increase of the number of horizontal wells and multi-branch wells, the increase of the drilling depth and the increase of the drilling depth. Generally, drilling fluids commonly used in drilling engineering are two systems of water-based drilling fluids or oil-based drilling fluids, and in order to overcome the problems of borehole wall instability and serious high-temperature viscosity increase of high-density oil-based drilling fluids when the existing oil-based drilling fluids are drilled into shale formations, a high-temperature-resistant high-density oil-based drilling fluid for drilling shale and a preparation method thereof are provided.

disclosure of Invention

The invention aims to provide a high-temperature-resistant high-density oil-based drilling fluid for drilling shale and a preparation method thereof, and aims to solve the problems of borehole instability and serious high-temperature tackifying of the high-density oil-based drilling fluid when the conventional oil-based drilling fluid drills into a shale stratum.

In order to achieve the purpose, the invention provides the following technical scheme: the high-temperature-resistant high-density oil-based drilling fluid for drilling shale comprises the following components:

240 portions of 0# diesel oil

2-4 parts of main emulsifier

1.5-2.5 parts of auxiliary emulsifier

2-4 parts of filtrate reducer

1-1.5 parts of organic soil

2-4 parts of lifting and cutting agent

1-2 parts of wetting agent

60 parts of 25% calcium chloride aqueous solution

Alkalinity regulator 2 parts

and 0-783 parts of barite powder.

Preferably, the fluid loss agent is prepared by reacting long-chain acrylate and acrylamide in a mass ratio of 1:3 at 70 ℃ for 6 hours by a dispersion polymerization method.

A preparation method of a high-temperature-resistant high-density oil-based drilling fluid for drilling shale comprises the following steps:

S1, taking materials: firstly, respectively weighing 2-4 parts of a main emulsifier, 1.5-2.5 parts of an auxiliary emulsifier, 2-4 parts of a cutting agent and 1-2 parts of a wetting agent, and weighing 240 parts of 0# diesel oil and 1-1.5 parts of organic soil;

S2, stirring: adding 240 parts of No. 0 diesel oil into a goblet, adding 2-4 parts of a main emulsifier, stirring for 5 minutes at a stirring speed of 10000 rpm, adding 1.5-2.5 parts of an auxiliary emulsifier at the same rotation speed, stirring for 5 minutes, adding 2-4 parts of a shear-improving agent at the same stirring speed, stirring for 5 minutes, adding 1-2 parts of a wetting agent, stirring for 10 minutes, adding 1-1.5 parts of organic soil under the stirring condition, stirring for 10 minutes, slowly adding 60 parts of a 25% calcium chloride aqueous solution, stirring for 10 minutes, sequentially adding 2-4 parts of a filtrate reducer and 2 parts of an alkalinity regulator, stirring for 20 minutes, adding 0-783 parts of barite powder, and stirring for 30 minutes at a stirring speed of 10000 rpm to prepare the high-temperature-resistant high-density oil-based drilling fluid.

Preferably, the method comprises the following steps:

S1, taking materials: firstly, respectively weighing 3 parts of a main emulsifier, 1.5 parts of an auxiliary emulsifier, 3 parts of a cutting agent and 2 parts of a wetting agent, and weighing 240 parts of 0# diesel oil and 1.5 parts of organic soil;

s2, stirring: adding 240 parts of 0# diesel oil into a goblet, adding 3 parts of main emulsifier, stirring for 5 minutes at a stirring speed of 10000 rpm, adding 1.5 parts of auxiliary emulsifier at the same rotating speed, stirring for 5 minutes, adding 3 parts of cutting agent at the same stirring speed, stirring for 5 minutes, adding 2 parts of wetting agent, stirring for 10 minutes, adding 1.5 parts of organic soil under the stirring condition, stirring for 10 minutes, slowly adding 60 parts of 25% calcium chloride aqueous solution, stirring for 10 minutes, sequentially adding 3 parts of filtrate reducer, 2 parts of alkalinity regulator, stirring for 20 minutes, adding 783 parts of barite powder, stirring for 30 minutes at a stirring speed of 10000 rpm, and thus obtaining the high-temperature-resistant high-density oil-based drilling fluid.

the invention provides a high-temperature-resistant high-density oil-based drilling fluid for drilling shale and a preparation method thereof, and the drilling fluid has the following beneficial effects:

The high-temperature-resistant high-density oil-based drilling fluid can be used for shale formations, and the oil-water ratio is 8: 2, resisting temperature of 180 ℃ and having a density of 2.2The drilling fluid has the advantages of good temperature resistance, high density, small temperature influence change of the rheological property of the drilling fluid, stable performance, wide application range, stable performance, high demulsification voltage, easy control of the rheological property of the drilling fluid under the conditions of high temperature and high density, small viscosity change of the drilling fluid under the condition of high temperature and solves the problem of high-temperature viscosity increase of asphalt filtrate reducer used by oil-based drilling fluid.

Drawings

FIG. 1 is a graph of the average kinetics of an aged precursor system of the present invention;

FIG. 2 is a graph of the mean kinetics of the system after aging at 180 ℃ in accordance with the present invention;

FIG. 3 is a graph of the average kinetics of the system of the present invention after aging at 200 ℃.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.