Production Pofile of Wells Before and After Treatment Using Novel ThermoChemical Technique

Abstract

Most of PETRONAS fields in Malaysia have been producing for more than 20 years. At this advanced stage of depletion, reservoir driving forces are low. Organic deposition, particularly in the near-and-around well bore region and in production tubing, can further reduce the production of oil by restricting the flow passage from reservoir to wellbore. A study to address this issue with a view to rejuvenate the problem wells through laboratory analysis & pilot field implementation was conducted. A unique thermo-chemical system has been developed as an effective tool for 1:Removing the organic deposits near-and-around wellbore and production tubing, henceEnhancing the production from the treated wells. The two components of the system are injected simultaneously into the wellbore through production tubing. Upon mixing, both components will produce heat and reaction products. The heat generated capable to melt and dislodge the organic deposits. While, the reaction products will act as an effective solvents and surfactants for dispersion of organic species. The objective of this paper is to present the result of 4 wells treated by the thermo-chemical system. Well selection criteria based on production profile and well history is described. The implementation technique and a post treatment production gain are also highlighted. INTRODUCTION Crude oil is a complex mixture of various hydrocarbon components. Under reservoir conditions of high temperature and pressure, the crude oil components exist in two phases (liquid and gaseous) under thermodynamic equilibrium with connate water attained over geological times. Heavy hydrocarbon components such as asphaltenes, resins and waxes, which at normal surface conditions are solids, exist in solution, either colloidal or disperse form, in liquid hydrocarbons. Similarly, light hydrocarbons which are in gaseous form under normal surface conditions, exist in solution and vapour forms under equilibrium with each other. When a well is put on production, the produced liquid and gaseous phases (water, oil and gas) are subjected to lowering temperature and pressure along production pathway and as such pass through a continuum of dynamic phase equilibrium. As a result, oil soluble solids (asphaltenes, resins and waxes), water soluble solids (scales) and soluble gaseous start separating out from the produced oil. These separated/precipitated organic solids under favourable hydrodynamic conditions have the ability to agglomerate, grow in size and diffuse from bulk to interphases (rock surfaces and pipe walls) and form deposits. The produced formation fines (sand, silt, clay etc), water borne scales and fine corrosion product can get oil wetted and act as excellent nuclei for the initiation and growth of organic deposit particularly waxes. Therefore, the actual oilfield deposits are composed of organic solids, scales, formation fines and trapped oil. The organic deposit can be predominantly parrafinic or asphaltenic in nature depending upon the nature of crude oil, change of temperature and pressure equilibrium, production rate, etc. The deposition can take place at all locations along the production pathway viz-a-vis around wellbores, in production tubings, surface facilities, flowlines, pipelines and storage tanks. Deposits around wellbore (causes formation gdamage reflected by high skin for the well) and in production tubing, adversely effect the well productivity.

An Experimental Study to Reduce the Fracture Pressure of High Strength Rocks Using a Novel Thermochemical Fracturing Approach

“…They successfully implemented this technology in twenty-three wells and observed that average production increased by 100%. Amin et al [44] also carried out a similar study to remove organic deposits in a brown field using thermochemical.…”