Tonner, David (Diversified Well Logging) | Swanson, Aaron (Diversified Well Logging) | Hollingshead, Ron (Diversified Well Logging) | Hughes, Simon (Diversified Well Logging) | Seacrest, Stephen (PetroLegacy Energy) | McDaniel, Bret (PetroLegacy Energy) | Leeper, Jay (Solid Automation)
From the very early days of oil and gas exploration, appraisal and development drilling, samples have been collected at the rig by mud logging personnel to conduct a preliminary geological analysis of the rock being drilled. This collection typically involves a sample collection recipient, board or bucket to collect a sample of rock over the desired interval. The sample is then sieved and cleaned in the appropriate way depending on the type of drilling fluid being used. As penetration rates have increased in some instances to more than 400 ft. / hr. the sample resolution has deteriorated exponentially. From an ergonomics perspective, the highest frequency to which a person onsite can collect a sample is once every 20 minutes. At 300 ft. / hr. this translates to 100 ft. of drilled rock. A new device has been developed and deployed which automates this manual process and thus ensures faster and more accurate collection of geological samples of the drilled rock interval. Sample resolutions of 5ft rock intervals have been attained at 400 ft./ hr. This technology has provided an important technological breakthrough and enables reduction of personnel at the rig site with a subsequent reduction in cost and HSE risk, particularly in areas of H2S. It further has provided for the potential integration with Measurement while drilling personnel. For both conventional and unconventional play development, this has provided oil and gas operators with an important and cost and risk reducing modus operandi compared to conventional drilling and evaluation techniques. The tool was deployed for an operator in West Texas where both manually collected traditional mudlog samples and automatically collected samples were taken. The samples were analyzed and compared for rock content. In addition, comparisons were made between point sampling with the automated system versus samples collected over a defined interval manually. Results of these comparisons will be presented.
A new method of automated drill cuttings sample collection has been successfully deployed. The new method provides a step change improvement in accuracy and resolution for sampling the rock record during drilling.
Additional data of the rock record provides potential insights to optimize wellbore placement and provide increased geo-mechanical data to optimize completions.
Tonner, David (Weatherford) | Davies, William (Weatherford) | AlMaslout, Karim (The University of Plymouth) | Forber, David (Weatherford International) | Pinna, Giovanni N. (Weatherford UK Ltd) | Chopty, James R. (Weatherford) | Jaipersad, Marlon Brent
Advances in drilling technology in response to a need for greater evaluation and exploitation of previously marginal resources are leading to increased usage of Controlled and Managed Pressure Drilling systems. Their application on High Pressure High Temperature wells is also increasing in relation to accurate flow and kick detection provision as well as pressure management. The benefits they bring in terms of hazard mitigation, reduced formation damage and improved drilling dynamics are allowing fields with tight operating windows to be drilled with greater safety margins and better economics. A consequence of using closed and pressured systems has been the impact and use of surface evaluation techniques, particularly surface gas logging.
Despite provision of real-time information relating to reservoir pressure, fracture gradient and fluid invasion as well as high resolution flow and fluid density variation, until recently there has still been a lack of meaningful surface gas information. This was due to the fact that all surface gas detection systems except for GC tracer currently rely on atmospheric conditions to extract gas from mud in air.
By utilising a semi-permeable membrane gas extraction process directly behind the choke manifold, prior to the Mud Gas Separator, the sampling point forms part of the enclosed system. This provides significant benefits in removing any potential surface gas loss. The application and deployment of such a technique is described in this paper. The responsive nature of membrane extraction, along with the repeatability and quantitative nature of the process, lends itself well to comparison with high resolution pressure and flow data generated by the Managed Pressure Drilling system and has the potential to be used to increase drilling efficiencies. The relationship between fluid composition and gas in mud volumes at surface, with derived reservoir pressure and surface parameters is examined in this paper.
Of the many different technologies and processes required to drill a well, none are more central to a successful drilling operation than those that control BHP (Bottom Hole Pressure) in both dynamic and static conditions. Such a system would be most beneficial to regions of known high pressure formations.