Why is an effective wellbore cleanout program essential when looking at the production and run life of a well?
Schlumberger: Movement of sand and accumulation of debris can have a considerable impact on fluid flow. On the surface, a river can deposit so much silt that it blocks its own flow, changing its course and perhaps threatening farmland and communities. Similarly, downhole in a well, influx of sand and debris can impair or stop the flow of oil or gas from a reservoir.
An effective wellbore cleanout is a critical step to restoring the production of a well, and enabling access to the wellbore and reservoir for subsequent evaluations or treatments that are a crucial part of the wells lifecycle.
Baker Hughes: Wellbore cleanout programs provide insurance to completion, workovers and production by basically reducing risks and NPT. The data has shown that more than 30% of NPT is the result of debris in the wellbore. This downhole debris can lead to many completion and workover problems such as a packer prematurely setting, screens getting blanked, safety valves malfunctioning, liner hanger not running to depth, etc. These problems can further affect production and reduce the life of the well.
Halliburton: First of all, any well loading with different type of deposits (sand, scale, wax, biofilm, corrosion byproducts, etc.) or any liquid loading in gas wells could result in flowing bottomhole pressure (FBHP) increase, decreasing production. The deposits can also damage perforations and filtration properties of wellbore area. All mentioned above could be a reason for a production decrease, intermittent production or even total well shut-down.
Any intrusion into the formation has potential for wellbore formation damage. Drilling and completion operations can leave drilling mud, fines, and water damage in normal operations. Any workover operation can also leave damage, such as rigid film emulsions after acid jobs in heavy oil, cooling of the formation from workover fluids to cause paraffin to deposit, CO2 flooding causing asphaltene deposits, swelling and scale from incompatible water use, and other problems. Fines can deposit in the wellbore area over time, reducing near wellbore permeability. Reduction of pressures and disturbances in fluid stability during production at the wellbore can cause scale, iron sulfide, biofilm, corrosion byproducts, and other damage, all leading to loss in production rates. Any of these can cause premature loss of production or water injection in the well.
Is wellbore cleanout adopted in both newly completed and mature wells across Russia?
Schlumberger: Accumulation of sand and solids in wellbores significantly impairs oil and gas production, regardless if it is a newly completed or mature well. However accumulation of sand/debris is more likely in a mature well, and hence the tendency is higher for a wellbore cleanout. In Russia it is also common to cleanout a newly completed well after a hydraulic fracturing operation has been performed.
Baker Hughes: In Russia, more and more operators have realized the importance of wellbore cleanout operations and have started to evaluate the risk vs. cost. We have seen increasing numbers of new wells using wellbore cleanout operations, especially in high cost wells. However, the cleanout operation is still very limited in mature wells in Russia.
Halliburton: It is difficult to say for the whole of Russia. It could vary from company to company. It is normal practice for a just-completed well to have a clean wellbore area. The problems in mature wells often are connected with not properly managed operations in the field.
In a new well, how can you measure the cost verses effectiveness of a cleanout program?
Schlumberger: The effectiveness of a cleanout can be measured by comparing the production gain following a cleanout against the well's true production potential (typically obtained from reservoir studies and recent well test results). The cost of the intervention is essentially the cost of the intervention service including all human resources, tools and fluids required to perform the cleanout. An economic analysis can then be performed to determine the pay back period to achieve the incremental production gain following the cleanout.
Baker Hughes: The operators need to evaluate the potential risks and NPT involved if the wellbore is not cleaned out. The risks can include prematurely set packers, failed screens, malfunctioning of downhole or surface equipment, etc. The risk and NPT related costs should be compared to the wellbore cleanout operations cost. The decision should be also be made considering the complexity and cost of the operations. In a low cost and simple completion operation, it may make sense to complete the well without a wellbore cleanout operation; however, in a complicated and high end well, the risk and cost of completion or workovers with debris in hole will be too high, and a wellbore cleanout operation is the best choice. In short, wellbore cleanout is the insurance premium paid to increase the life of the well and ultimately production.
Halliburton: The main factor of effectiveness and cost of a cleanout program is the time required for the cleanout operation. Controlling this parameter can give us the possibility of reducing costs and increasing the effectiveness of the technology selected for cleanouts. Again, each new well has to have a clean wellbore area in order to provide the best possible production.
Cost effectiveness is measured by ROI of the treatment and achieving predicted well production. If a new well is not producing at the expected rate then wellbore damage from drilling and completion operations should be investigated. Wellbore cleanout cost (chemical, application, and production lost cost) should be determined and compared to expected production to decide on the treatment and also compared to the resulting production change after treatment to decide if the treatments are worthwhile.
Wellbore cleanout is not a one-size-fits-all service; it demands adaptability and proven technology. Vigor Petroleum's unwavering commitment to this critical discipline – through continuous investment in R&D, technical expertise, and cultivating a vast supplier base – directly translates into reliable, effective solutions for diverse well conditions worldwide. This dedication is why Vigor's wellbore cleanout tools consistently receive high acclaim from renowned operators across the globe. Trust Vigor for your essential cleanout needs. Contact our expert engineering team to discuss customized downhole solutions for drilling, completion, logging, or well intervention. For more information, you can write to our mailbox info@vigorpetroleum.com & mail@vigorpetroleum.com.
