Tubing scale removal for well G098-51
Case In Brief
- On April, 2019 it was found a Hard scale @ tubing head.
- The internal diameter of the production tubing (31/2 EUE) was after scale accumulation 1.8 inch.
- The production data shows 800 BOPD against pressure 140 PSI
- XRD analysis for the scale sample Shows the following;
| Semi-quantitative analysis obtained by X-Ray diffraction for scale sample | ||
|---|---|---|
| MINERALOGY (WEIGHT%) | ||
| Mineral Name | Aragonite | Weight(%) |
| Percentage | 100 | 100 |
| Chemical Structure | CaCO3 | |
| Crystal Shape |  |
|
Challenge
- Scale formed in the tubing that diminish the total production and pressure.
- The scale formation caused reducing the internal diameter of the tubing thus limiting the accessibility to change or maintain the down hole tools
- The tubing end is open to formation and the bottom hole pressure is not compensating the hydrostatic head of the chemical to assure the contact time needed to dissolve the scale so the chemical must be delivered through coiled tubing in a very special technique.
Solution
Solubility test was performed for the scale with SAPESCO Chemical new formulation SCSR-08 in ambient conditions indicating an effective formulation with an outstanding and remarkable dissolution of the scale.
Results
- The new SAPESCO Chemical (SCSR) provided a new solution to remove the tubing scale and restoring the full capacity of the tubing by increasing the production from 800 bbl./day to 912 bbl./day
- Achieving the accessibility to the downhole in order to retrieve the downhole completion tools by increasing the internal diameter of the tubing from 1.8 inch to 2.75 inch.
DIAGNOSIS AND ANALYSIS
| Well# G98-51 | Before | After |
|---|---|---|
| ID (inch) | 1.8 | 2.75 |
| Pressure (PSI) | 140 | 230 |
| Production (net) | 800 | 912 |
The well performance after the job showed outstanding results through increasing the net production and clean the tubing from any formed scales.
These results indicate that the chemical treatment succeeded to remove the scale formed in the tubing by designing a new chemical formulation and special operational design suitable for cleaning the whole tubing from the formed deposits and safe on formation matrix.