Abstract
This study evaluates the corrosion inhibition performance and compatibility of UBPro-160, a high-efficiency acidizing corrosion inhibitor, with two intensifiers — HYtem 382 and HYtem 410 — under high-temperature oilfield acidizing conditions. L80 steel coupons were exposed to a 12% HCl / 3% HF acid system at 150 °C with 60 rpm rotation for 6 h and 12 h. Corrosion rates were determined from post-exposure weight loss and used to assess inhibitor efficacy and synergy. Results provide guidance for selecting field acidizing formulations.
1. Introduction
1.1 Background
In oilfield stimulation, hydrochloric acid (HCl) and hydrofluoric acid (HF) are employed to dissolve carbonate and siliceous formations. Their aggressive nature can severely corrode downhole tubulars and surface equipment, necessitating the use of corrosion inhibitors. UBPro-160 is a high-efficiency inhibitor designed for acidizing environments, while HYtem 382 and HYtem 410 are intensifiers intended to boost inhibition performance, particularly at elevated temperatures.
1.2 Objective
- Evaluate the corrosion inhibition performance of UBPro-160 in combination with HYtem 382 and HYtem 410 at 150 °C, with rotation at 60 rpm for 6 h and 12 h, in a 12% HCl / 3% HF system using L80 steel coupons.
- Assess compatibility between UBPro-160 and the two intensifiers (synergistic or antagonistic effects) under the test conditions.
1.3 Scope
Experimental format: rotating-cell corrosion tests on L80 coupons in acidic media. Primary metric: corrosion rate (CR), expressed in lb/ft²·h.
2. Materials and Methods
2.1 Test materials
| Category | Item | Role |
|---|---|---|
| Steel coupon | L80 | Standard tubular grade specimen |
| Inhibitor | UBPro-160 | High-efficiency acidizing corrosion inhibitor |
| Intensifier | HYtem 382 | High-temperature performance booster |
| Intensifier | HYtem 410 | High-temperature performance booster |
2.2 Test solution and conditions
| Parameter | Value |
|---|---|
| Acidic medium | 12% HCl + 3% HF (by volume) |
| Temperature | 150 °C |
| Rotation speed | 60 rpm |
| Exposure durations | 6 h and 12 h |
2.3 Experimental setup
Coupons were cleaned, dried, and weighed according to standard surface preparation procedures prior to exposure in a high-temperature rotating corrosion cell. Three formulations were tested:
- UBPro-160 alone (control)
- UBPro-160 + HYtem 382
- UBPro-160 + HYtem 410
2.4 Measurements
Coupons were cleaned and descaled per standard protocols after exposure, and weight loss was used to calculate corrosion rate:
ΔW — weight loss of coupon (lb)
A — exposed surface area (ft²)
t — exposure time (h)
2.5 Quality control
A baseline corrosion test using acid only (no inhibitor) was conducted to establish a reference corrosion rate.
3. Results
3.1 Compatibility assessment
Compatible UBPro-160 is compatible with both HYtem 382 and HYtem 410 under all tested conditions.
Best synergy Both intensifiers improve UBPro-160 performance; HYtem 410 provides the most significant synergy, yielding a lower corrosion rate than either component alone.
3.2 Representative observations
- No pitting observed on any coupon across all formulations.
- HYtem 410-treated coupon surfaces were covered with an antimony (Sb) salt layer.
4. Discussion
5. Conclusion
In the 12% HCl / 3% HF system at 150 °C and 60 rpm, UBPro-160 alone provides fair corrosion-control performance.
Both HYtem 382 and HYtem 410 intensifiers improve UBPro-160 performance, with HYtem 410 delivering the most significant synergy — a lower corrosion rate than either component used alone, with no pitting observed.