Imbazi, Oyeintonbra (Shell Company in Nigeria) | Ugoh, Oluwatobi (Shell Company in Nigeria) | Okoloma, Emmanuel (Shell Company in Nigeria) | Osuagwu, Micheal (Shell Company in Nigeria) | Enyioko, Chigoziem (Halliburton) | Ighavini, Emmanuel (Halliburton) | Uzodinma, Chioma (Halliburton)
Well 01 and Well 02 are part of the phase 1-6 project that involved the development of six wells with the potential to deliver an additional 70% production increase to the LNG export market. The sand face for both wells was drilled with 0.72psi/ft pseudo oil-based mud (POBM). After the initial well clean-up, both wells produced sub-optimally (~20% of estimated potential) with relatively high drawdown (ranging from 500psi – 1000psi). This low production was suspected to be because of downhole (screen and formation) impairment or partial opening of the formation isolation valves (FIV).
A restoration team was set up with a responsibility to proffer a robust well intervention execution plan and select the most potent barite dissolver. Nine stimulation chemicals were tested and based on the team criteria, CHEM-001 and CHEM-002 were selected as main-treatment and pre-flush chemicals, respectively.
The downhole and surface conditions that exist in deep high-pressure wells pose many challenges to the coiled tubing industry as it strives to provide safe and reliable access to the wells. This paper highlights a case history of successfully snubbing coiled tubing (CT) into two deep (about 14,000ft+) live wells (Well 01 and Well 02) with a high surface pressure (7000psi+) and temperature (80 – 100°C) to stimulate both wells. The success criteria post stimulation was targeted at 75% of the potential production value. However, post treatment results show that cumulative gas production increased by 375% (with about 200psi) with a potential to increase up to 400%.
This paper details the entire operations during the CT well intervention, the planning, design, and technical analysis which led to the selection of a CT with 130,000psi yield strength on a 125K CT injector system, force simulations, and laboratory tests on CT with stimulation chemicals which led to a successful stimulation campaign. The paper also covers the initial planned versus actual operations and the lessons learned leading to on-the-spot optimization plans that resulted in a highly successful intervention operation.
Jin, Ningjing (Vertechs Oil & Gas Technology Co., Ltd.) | Xiao, Shuyue (Exploration and Development Research Institute, PetroChina Southwest Oil and Gasfield Company) | Zhang, Shuo (Vertechs Oil & Gas Technology Co., Ltd.)
The paper will include an introduction of dissolvable plug and its development in oil & gas upstream business. Dissolvable plug is a customized tool, and it could be modified by controlling its chemical compound to adjust its dissolving rate. In addition, slim version dissolvable plug is a plug solution with dissolvability originally brought out to overcome the downhole restriction challenge (ID of SSD), namely to pass the downhole restriction then to set in the original casing ID. A case study of its application in offshore squeeze cementing job will be analyzed in this paper, from the plug designing perspective to operational data recap to prove its benefits. Conventional plugs will leave the bottom of the plug body downhole after plugs slip losing integrity during the milling operation, and the remainder leaving downhole will choke the well production or even block the well, however, dissolvable plug remainders will dissolve itself downhole, which will not have an impact on the production.