Deep Matrix Acidizing

Deep Matrix Carbonate Acidizing

Deep matrix acidizing involves uniformly increasing the permeability of the rock matrix to 10-20 ft (about 3-6 m) radius around the wellbore in a producer or injector well.  This type of stimulation is ideal for situations where the productivity or injectivity of a well is low due to low matrix permeability rather than near wellbore damage. 

Uniform acidizing is very difficult or impossible to achieve with conventional acids which react on contact with the carbonate formation forming wormholes rather than uniformly acidizing the whole rock matrix.   

An ideal matrix acidizing system, so highly retarded that no reaction takes place while the acid is pumped into the reservoir, has been described.  This hypothetical system has been proposed as the ultimate for a matrix treatment (REF: Acidizing Fundamentals (1979). Williams B.B. et al, SPE Monograph No. 6 New York and Dallas).  Arcasolve™ is very close to this ideal system.  Over 95% of the total acid produced is generated down hole after the treatment fluid has been pumped to fill the rock matrix.   This provides excellent uniform acidizing throughout the fluid filled zone and highly effective matrix stimulation. 

Theory indicates that in undamaged formations, increases in production rate of the order of 20% can be obtained by increasing the permeability of the formation about 3-4 fold to a radial distance of 10-15 ft.

There is a practical limit of about a 50% increase in injectivity or productivity that can be achieved using matrix stimulation of undamaged oil or water wells.  Higher levels of stimulation would probably require the use of uneconomic volumes of Arcasolve™ stimulation fluid (acid generating solution) as the volume required to fill an expanding circumference is a squared function of the radius i.e. if the depth of penetration is doubled the required volume increases 4-fold.  It is important when designing jobs that a balance is struck between the volume pumped (cost of job) and the resulting increase in production. The expected change in production or injectivity for different treatment volumes can be estimated using suitable simulation software to determine the optimum volume to use on a cost/benefit basis. 

Matrix stimulation may be particularly appropriate in situations where stimulation by fracturing might lead to problems such as reduction of sweep efficiency of water floods or there is a risk of increasing  the water cut.  Deep matrix acidizing with Arcasolve^TM may usefully be combined with damage removal treatments or stimulation of natural or induced fractures.

If you have specific candidate wells for DEEP MATRIX ACIDISING TREATMENTS, you can send us details by completing the submission form on this web site.  This will allow us to identify the specific Arcasolve^TM formulation and treatment fluid volume required before we reply to you.