Accessing bypassed oil to capture bypassed cash-flow
The oil and gas industry has been hard-hit by the economic downturn. We find ourselves dealing with an unprecedented situation: most financing channels are at punitive rates, and the equity capital markets are an option only for a select few. With oil prices only slowly recovering, there is an industrywide sense of urgency to identify ways to lower costs, make more barrels, and deliver a positive cash flow through high-value activities such as rigless interventions and attractive surface opportunities. Operators seeking faster monetization of assets with predictable project cost and execution are emphasizing production growth and reserve recovery through access of bypassed oil.
Halliburton combines new exploration and production technology with global experience and reservoir expertise, to help operators unlock the economic potential of mature fields by finding new oil, optimizing production and improving overall asset recovery.
A “Mature field” typically refers to fields that have reached their peak production based on economic limits after primary and secondary recovery efforts. Primary recovery factors are typically below 35 percent with large amounts of oil and gas remaining in mature fields. One of the first challenges in mature field development is to find this remaining bypassed oil. Why has the oil been bypassed? Typically as a result of suboptimal field development planning, inefficient displacement (residual oil in the pores) or poor sweep efficiency during water flooding. When analyzing a mature field, best practices include identifying bypassed zones, determining remaining recoverable fluids and identifying better permeability zones that are damaged and can be simply re-perforated via a vertical well. In other words, there’s no need for an expensive workover operation where a simple vertical well will do the trick.
Conventional completions techniques require a workover operation to re-complete these potential hydrocarbon zones. However, due to the presence of production from existing zones below the proposed re-completion –as typified in a dual completion (figure 1) where the long string is still producing while the short string is shut-in –a workover is not an economic option to recover these zones.
So what’s the solution?
Halliburton has developed a novel cement packer technology to be able to re-complete these zones without pulling out the existing completion. Pressure isolation of potential zones is accomplished by placing cement in the tubing-casing annulus above the production packer; the cement acts as a new production packer farther up the wellbore. The cement packer then isolates the objective zone from the surface and below so that all production is through the tubing. Conventional or oriented perforating is then used to complete the well in the new productive intervals.
While the number of well configurations, depths and deviation profiles is endless, there are generally two methods used to place cement packers: via coiled tubing or circulated down the production tubing. Pre-job planning, quality assurance/quality control, and placement techniques are critical to obtaining a long-term hydraulic seal. Cement packer completions are a unique and cost-efficient method for recovering reserves from stacked hydrocarbon reservoirs previously ignored because of the economic restrictions of major rig workovers. In this case, the tubing is cemented in place inside the casing or open hole. This has been successfully field tested and provides a means to achieve future plugbacks purely through wireline.
Halliburton has a packer for every type of completion – our cement packer is proven in various prolific reservoirs in both clastic and carbonate systems. For more than 75 years, our production packers have delivered innovation and top performance, helping operators maximize the value of their assets through greater production and lower costs. For rigless access to shallow bypassed oil, Halliburton is your best bet.
“Leveraging Emerging Technologies to Increase Production from Unconventional Reservoirs: Case Study of India,” Y.K. Choudary, SumitBhat, and A. Kumar, Halliburton, presented at the 2012 International Petroleum Technology Conference, Feb. 7-9, Bankok, Thailand.
“Cement Packer: An Innovative Technique to Recover Reserves Above Packer Without Re-completion”, Yoliandri Susilo, SPE; Wahju Wibowo, BP Indonesia; David Rich, SPE, BP UTG Aberdeen. SPE 78493.
“Rigless Multi-zone Re-completion Using a Cement Packer Placed with Coiled Tubing: A Case History” T.W. Nowak and T.S. Patout, SPE-35613-PA.