Summary
• | Even if the total injection rate is constant, the |
| injection rate into each zone can be a |
| function of time. |
• | There is nothing mysterious or unexpected in |
| cross flow. |
• | Flow rate can be large enough to carry fines |
| and sands into injection string. |
• | Immediately following shutdown, cross flow is
| from low perm zone to high perm zone. |
| Cross flow can reverse direction. |