WELL INFORMATION
- 6,500ft (1980m) TVD
- 17,000ft (5180m) TMD
- 215oF BHST
CHALLENGE
Bradenhead gas of greater than 200psi (1.4 MPa) after completion of Production Cementing
SOLUTION
- Proper Spacers/Preflushes
- Proper Cement blend design combined with Magnum additive technology.
- Provide a slurry with enhanced mechanical properties and bonding.
RESULTS
- Highest industry success rate for mitigating Bradenhead gas in DJ basin.
- Achieved proper casing and formation bond.
- Provided client with efficiencies to achieve overall well integrity.
OVERVIEW
The DJ Basin is a large formation located in northeastern Colorado and southeastern Wyoming. A major oil and gas producer in this region encountered a significant bradenhead gas challenge. Bradenhead gas, also known as a surface casing vent flow (SCVF) is a serious well integrity concern that will increase remedial and/or abandonment costs and poses a potential HSE (health, safety, and environment) risk if not solved.
CHALLENGE
An operator had a significant number of wells with Bradenhead gas pressure, >200psi (1.4 MPa) cementing production casing. Many different process and technologies were attempted with other cementing service companies resulting in little improvement. The Colorado Oil and Gas Conservation Commission (COGCC) requires testing, reporting, constant monitoring and potential remediation be provided for each well with Bradenhead gas of >200psi (1.4 MPa) is present.
SOLUTION
Magnum worked with the operator to understand the cause of the Bradenhead gas pressure, then developed an optimized cementing process that achieved a high industry success rate for overcoming Bradenhead gas.
- An advanced spacer and preflush combination was designed to provide sufficient displacement of the drilling fluid and removal of the filter cake to ensure adequate cement bonding.
- A proprietary cement blend with high reactivity and high solids content was used to prevent gas migration and provide a quick transition time preventing short term gas migration. The high solids content provided the set cement with a very low permeability to mitigate gas migration.
- Specialty additives further complimented the overall design by providing proper pump time, viscosity, ductility, and bond enhancement.
- Accurate and reliable cementing equipment provided all pumping operations to be completed within the designated density control and pumping rate limits. This ensured the cement blend performed as designed throughout the entire wellbore.
RESULTS
Cement-to-casing and cement-to-formation bonding was achieved providing optimal hydraulic isolation across formations stopping Bradenhead gas. Proprietary technology was applied which consisted of; proper rheology and yield point design of the spacers/preflushes, enhanced lead and tail cement blends with gas migration control additives, and proper mix/pump rates to successfully place the cement mitigating Bradenhead gas channeling.
