In the oil and gas industry, chasing refers to a crucial operation used to determine the open status of a wellbore. This process involves running a pipe through the wellbore to assess its patency and identify any potential obstructions or blockages.
The Goal:
The primary objective of a chase operation is to confirm the wellbore's accessibility and its ability to accommodate the planned intervention. It helps determine:
The Process:
The chase operation involves several key steps:
Types of Chasing Operations:
Depending on the purpose and conditions, various types of chasing operations are employed:
Benefits:
Conclusion:
Chasing is an essential part of wellbore management, ensuring efficient and safe operations. By understanding its purpose, process, and various types, industry professionals can make informed decisions and optimize wellbore performance for maximum productivity and profitability.
Instructions: Choose the best answer for each question.
1. What is the primary goal of a chasing operation? a) To clean out debris from the wellbore. b) To measure the exact depth of the well. c) To determine the wellbore's accessibility and identify obstructions. d) To stimulate oil production in the well.
c) To determine the wellbore's accessibility and identify obstructions.
2. Which type of chasing operation involves running the pipe against an obstruction to test its resistance? a) Simple Chase b) Bumping Chase c) Wireline Chase d) Casing Chase
b) Bumping Chase
3. What is the main benefit of conducting a chasing operation? a) Increased oil production. b) Reduced downtime and improved safety. c) Accurate measurement of the well's depth. d) Easier access to the wellbore for maintenance.
b) Reduced downtime and improved safety.
4. What type of pipe is typically used for chasing operations? a) Plastic tubing b) Wooden beams c) Steel drill pipe or casing d) Aluminum wire
c) Steel drill pipe or casing
5. Which of the following is NOT a type of chasing operation? a) Simple Chase b) Bumping Chase c) Wireline Chase d) Drilling Chase
d) Drilling Chase
Scenario:
You are an engineer preparing for a planned workover operation in a well. A recent chasing operation revealed the following data:
Task:
Analysis: The chasing operation indicates a potential obstruction or blockage at 7,800 ft, preventing the casing from reaching the target depth of 8,500 ft. This could be due to: * **Debris or sediment buildup:** A significant amount of debris or sediment might have accumulated in the wellbore. * **Collapsed casing:** A section of the casing might have collapsed, partially blocking the passage. * **Stuck equipment:** Previously used equipment might be lodged in the wellbore. * **Unexpected formation changes:** Unexpected changes in the formation might be creating a tighter passage for the casing.
Potential issues for the workover operation: * **Inability to reach the target depth:** The obstruction might prevent the necessary equipment from reaching the intended zone. * **Increased risk of equipment damage:** Running equipment against the obstruction could cause damage to the equipment or the wellbore. * **Delayed operation:** Time and effort might be required to remove the obstruction before proceeding with the workover operation.
Suggested Actions: * **Further investigation:** Conduct a detailed investigation using wireline logging or other appropriate methods to determine the exact nature of the obstruction. * **Removal of the obstruction:** If feasible, attempt to remove the obstruction using specialized tools or techniques. * **Alternative intervention plan:** If removing the obstruction is not possible or too risky, consider an alternative intervention plan that accommodates the existing condition. * **Safety precautions:** Implement safety protocols to minimize risks associated with working around the obstruction.
Comments