Delayed Boron Crosslinking Agent Water Based Fracturing Fluids Crosslinked

Delayed boron crosslinking agent,T-OG008

Delayed boron crosslinking agent

Features and Applications

The crosslinking process of boron ions is reversible, and it can re-crosslink the polymer macromolecules of the fractured fluid that are mechanically sheared, restoring the viscosity of the fractured fluid. The frozen gel of the fractured fluid crosslinked by the delayed boron crosslinking agent system has the advantage of resistance to mechanical shear.

Using the delayed boron crosslinking agent system can greatly reduce the chance of the macromolecules of the fractured fluid freezing gel being sheared during the pumping process, which has the effect of protecting the performance of the fractured fluid.

Using the delayed boron crosslinking agent system is beneficial for the dispersion of the crosslinking agent, improving the viscosity of the fractured fluid and increasing its temperature stability. The use of the delayed boron crosslinking agent system can significantly reduce the pumping friction during construction, which is of great significance for ensuring the service life of fracturing equipment and the success of fracturing construction.

The delayed boron crosslinking agent system is easy to use, simplifies on-site construction, and saves construction costs. The delayed boron crosslinking agent is composed of A agent, a suspension of boron minerals, and B agent, a catalyst, and the ratio of the two agents can be adjusted to meet different gelation time requirements. The delayed boron crosslinking agent can be used to crosslink semi-xyloglucan-based water-based fracturing fluids. The guargum and hydroxypropyl guar gum water-based fracturing fluids crosslinked by the delayed boron crosslinking agent system can be used for sand fracturing construction in oil and gas wells with wellbore temperatures ranging from 50 to 150℃ and other downhole construction operations.

Technical specifications

Item                                                             Specification

                                    Component B                                     Component A

Appearance    Colorless or pale yellow or light brown liquid Colorless liquid

pH                                  5.0～10.0                                            12.0～14.0

Density (20℃), g/cm3   1.10～1.30                                           1.10～1.20

Gelation Time Range, min 0.4～15 —

Solubility — No layering, turbidity, or precipitation

Recommended Dosage

1.Base Fluid Preparation (Reference)

0.35%-0.65% Hydroxypropyl Guar Gum, +0.1%-0.2% pH Adjusting Agent, +0.3% Biocide, +0.5% Clay Stabilizer, +0.5% Surfactant, +1.0%-2.0% KCL. After adding guar gum powder, stir for 2 hours and wait for complete hydration of the guar gum. The pH value should be 9-11.

2.Delayed Crosslinking Time Adjustment

The delayed gelation time of the boron crosslinking system is achieved by adjusting the ratio of the main agent and catalyst of the delayed boron crosslinker. Reference data is shown in Table 2. The delayed gelation time range in Table 2 is for reference only. Accurate data should be determined by on-site water sampling experiments during construction. In the experiment, the mixed crosslinker should be used as soon as possible. About 1 hour before pumping during construction, the delayed boron crosslinker main agent and catalyst should be mixed in proportion and stirred evenly for standby. The standing time should not exceed 3 hours, otherwise it will cause boron mineral precipitation and affect the accuracy of measurement.

3.Determination of Crosslinking Ratio

Table 2 Delayed Gelation Time Range

Mixing Ratio of Crosslinker Full Gelation Time

Delayed Boron Crosslinker Main Agent, g Catalyst, g

100 15 9’50”

100 20 4’30”

100 25 2’30”

100 30 30”

The recommended dosage of the delayed boron crosslinker system is between 0.15%-0.4% (V/V). During the crosslinking ratio selection experiment, the dosage of the crosslinker can be increased gradually, and the frozen gel viscosity will gradually increase. When the dosage of the crosslinker increases to a certain point, the frozen gel viscosity reaches a certain well design value, and the crosslinking ratio at this point is determined.

Product Packaging

The delayed boron crosslinker main agent is packaged in a 50kg plastic drum and the catalyst is packaged in a 25kg plastic drum ,Other specifications can be agreed upon in the contract.

Transportation and Storage

The product should be stored in a ventilated and cool place, away from fire. The product should be handled with care during transportation and storage, and the sealing of the packaging drums should be protected to prevent leakage and affect the accuracy of measurement.