Application of Vapor Acid Matrix Acidizing in Clastic Reservoir: Laboratory Test and Field Trial Conference Paper uri icon

abstract

  • Abstract A new method of acid matrix stimulation treatment was deployed in offshore Field S to remove formation damage in one of the gas producers. The new method involved deploying an inert stable solid chemical stick downhole via wireline. Once deployed downhole and activated to burn, heated vapor of Hydrochloric Acid (HCl) and mud acid is generated in sequence to react with the formation and the well is then ready for flowback after four hours of soaking. This new method has effectively simplified acid stimulation treatment operations by eliminating pumping operations using barge, which resulted in a more cost-effective solution. The treatment consisted of HCl and mud acid only, which is an uncommon practice for a typical acid matrix treatment for clastic formation. Without additives, solid precipitations are a major concern as it can cause further damage to the near wellbore region. Hence, extensive laboratory analysis were conducted on the reservoir core samples to investigate the effect of 15% HCl and mud acid without any additives. The main objective was to determine the return permeability post acid treatment and subsequently evaluate potential solid precipitations. The laboratory analysis conducted were coreflood, dissolution and compatibility test. Coreflood test results showed reduction in permeability post treatment by 25% due to solid precipitations which was further identified through mineralogy and Inductive Coupled Plasma (ICP) analysis after the acid treatment. The dissolution test showed 10% to 11% of overall sample weight loss. This paper describes the details of the laboratory analysis and findings from the job execution of pure acid stimulation treatment (without additives) for a clastic formation. Best practices and lessons learnt during job preparation and execution will be discussed to provide insights for future technology replications.

authors

  • Razali, A. Mohammad
  • Berok, S. M. James
  • Lee, Q. Z.
  • Yeap, W. J.
  • Ahmad, N. A.
  • Ismail, W. R. Wan
  • Sidek, S.
  • Jeffry, S. Mohd
  • Mohamad, W. A. Wan
  • Madon, B.
  • Dzulkarnain, Iskandar bin

publication date

  • 2024

start page

  • D031S026R004