I. Characteristics of oil-based drilling fluid
Shandong Juxin New Material Co., Ltd. has developed two sets of oil-based drilling fluids, which have common characteristics:
(1) The emulsification stability is good, and the demulsification voltage before and after hot rolling is above 800V;
(2) Good thermal stability, can withstand a temperature of 200°C, after 16 hours of hot rolling, if the hot rolling continues for 48 hours, 72 hours or even 96 hours, the rheological properties of the drilling fluid will not change much;
(3) The dosage of treatment agent is small, the dosage of main milk, auxiliary milk and wetting agent is all below 3%, which saves drilling cost;
(4) The fluid loss is low, and the fluid loss after hot rolling is less than 8ml.
II. Treatment agent
1. Main emulsifier (JC-ZR)
The lipophilic group of the main emulsifier is a comb-shaped molecular chain, which not only has emulsifying properties, but also has the functions of thickening and cutting, and can withstand temperatures up to 220°C. The oil-based drilling fluid prepared with JC-ZR1# has slightly lower shear force; the oil-based drilling fluid prepared with JC-ZR2# has slightly higher shear force.
2. Co-emulsifier (JC-FR)
The lipophilic group of the auxiliary emulsifier is a straight chain molecule, and its molecular volume is smaller than that of the main emulsion. In addition to emulsification, it has the effect of reducing viscosity and shear, and can resist temperature up to 220°C.
3. Wetting agent (JC-RS)
The lipophilic group of the wetting agent is a straight chain molecule, and the chain length is equivalent to that of the main milk lipophilic group. It has the functions of emulsification, wetting, viscosity reduction, and shear reduction, and its temperature resistance is 200°C.
4. Cutting agent (JC-GT)
Ether polymer, used to improve the dynamic shear force of oil-based mud.
5. Organic soil
High temperature resistant organic soil is recommended: JC-T1#/JC-T2#.
Medium and low temperature organic soil is recommended: JC-T1#.
6. Anti-high temperature fluid loss reducer
Anti-high temperature fluid loss reducer High softening point natural asphalt or petroleum asphalt.
III. Processing agent compatibility
The structures of JC-ZR, JC-FR and JC-RS ideally match the structure of hydrophilic group and lipophilic group, realizing the unification of viscosity increasing, shear raising, viscosity reducing, shear reducing and emulsification. The division of labor is clear in the adjustment of variable parameters, which is convenient for field engineers to adjust the performance of drilling fluid.
The special molecular structure of the wetting agent JC-RS makes the surface of the weighting agent change from water wetting agent to oil wetting, and at the same time realizes the effect of reducing viscosity and reducing shear, and at the same time enhances the emulsification stability and thermal stability of drilling fluid, greatly The amplitude increases the demulsification voltage of the drilling fluid and reduces the fluid loss of the drilling fluid.
IV. Recommended dosage of treatment agent
1# main milk JC-ZR1#: 0.8%-1.5%;
2# main milk JC-ZR2#: 0.8%-1.5%;
Auxiliary milk JC-FR: 1.8%-2.5%;
Wetting agent JC-RS: 0.8%-1.3%;
Cutting agent JC-GT 0.3%-0.5%
Organic soil 1%-1.5%
Fluid loss additive: 4%-5.5%
Calcium oxide 1.5%-5%.
V. Preparation steps
The total configuration time is 60 minutes.
(1) Measure a certain volume of oil and pour it into a high stirring cup, add main milk, auxiliary milk, wetting agent, and stir at high speed for 5 minutes;
(2) Measure a certain volume of calcium chloride aqueous solution and pour it into a high stirring cup, and stir it at high speed for 15 minutes;
(3) Weigh the organic soil, calcium oxide and fluid loss control agent into the high stirring cup respectively, and continue stirring at high speed for 10 minutes;
(4) Add barite into the high stirring cup, stir at high speed for 25-30 minutes, and the total configuration time is 60 minutes.
(5) Measure the performance of the drilling fluid at 65°C (150°F). The ES is measured at 50°C after stirring for 1 min after the performance measurement.
(6) Determination of the complete set of properties of the drilling fluid after thermal rolling.
VI. Matters needing attention
(1) If the shear force (dynamic shear force and static shear force) of the oil-based drilling fluid prepared by the 1# main emulsion system is slightly low, 0.1-0.3% of the shear lifting agent can be added.
(2) If the shear force (dynamic shear force and static shear force) of the oil-based drilling fluid configured in the 2# main milk is slightly high, the amount of organic soil can be appropriately reduced.
(3) During storage and use, direct contact with open flames and human body is prohibited. After accidental contact, it can be cleaned with detergent and clean water.
