Non-Acidic Stimulation Fluid for High Temperature Sandstone

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Solution Overview

Problem

Traditional acid-based stimulation methods for sandstone formations at high temperatures are limited by instantaneous reactions and precipitation issues, leading to formation damage and reduced treatment efficiency.

Innovation Solution

A non-acidic stimulation fluid method involving a three-step process: preflush brine injection, followed by a sodium or potassium hydroxide solution, and then an overflush brine, which allows for deeper penetration and avoids precipitate formation, using preheated solutions to enhance reaction time and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional acid-based stimulation fluids (HF, HCl) are used in sandstone formations, then formation minerals and contaminants are effectively dissolved, but instantaneous reaction limits penetration depth and precipitate formation causes formation damage

Engineering Contradiction:

Improvedissolution of formation minerals and contaminantsVSAvoidpenetration depth into formation

Core Design Contradiction:

Quantity of substanceVSLength of moving object

Solution Approach 1:

The patent changes the chemical parameters of the stimulation fluid by using non-acidic alkali metals (NaOH, KOH) instead of traditional acids (HF, HCl). This fundamental parameter change alters the reaction kinetics from instantaneous to controlled, enabling deeper penetration while maintaining effective mineral dissolution through alternative chemical mechanisms that do not produce precipitates.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent inverts the traditional acid-based approach by using base-based stimulation fluids. Instead of dissolving minerals with acids, the invention uses alkali solutions that react with formation minerals through base-rock reactions, fundamentally reversing the chemical approach while achieving the same stimulation objective without the harmful side effects of acid treatment.

Inventive Principle:

Principle #13The other way round (Inversion)

2Quantity of substance

If traditional acid-based stimulation fluids are used in high temperature sandstone formations, then formation minerals are dissolved, but precipitate formation aggravates formation damage at higher temperatures

Engineering Contradiction:

Improvedissolution of formation mineralsVSAvoidformation damage from precipitates

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of temperature (which accelerates precipitate formation in acid treatments) into a beneficial factor by using non-acidic fluids. The higher temperatures enhance the effectiveness of the alkali-based stimulation without causing the precipitate problems that plague acid treatments, turning a previously harmful condition into an advantageous operating parameter.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical composition parameter from acidic to basic/alkaline, fundamentally altering how temperature affects the stimulation process. In the non-acidic system, high temperatures enhance reaction effectiveness without triggering the precipitate formation mechanism that occurs in acid-based systems, thereby eliminating the temperature-related harm.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If traditional acid-based stimulation fluids are used, then formation minerals are dissolved, but the instantaneous reaction rate limits treatment efficiency

Engineering Contradiction:

Improvedissolution of formation mineralsVSAvoidtreatment efficiency and penetration depth

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent changes the kinetic parameter of the chemical reaction by substituting acid with alkali-based fluids. This parameter change transforms the instantaneous reaction characteristic of acid treatments into a controlled, sustained reaction that maintains effective mineral dissolution while enabling deeper and more efficient penetration into the formation over time.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The non-acidic stimulation fluid achieves deeper penetration and prevents formation damage by reacting slowly with sandstone, increasing permeability and treatment efficiency while avoiding precipitates, even at high temperatures.

Implementation Method 1

The non-acidic stimulation fluid has a slower reaction time with the sandstone formation, thereby allowing for deeper penetration into the formation

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

using preheated solutions to enhance reaction time and efficiency

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

the non-acidic stimulation fluid does not form precipitations after reaction with the sandstone formation that can damage the wellbore upon further stimulation techniques

Methodology Applied

Scientific EffectPrecipitation prevention: Precipitation

Data Source

PatentUS9334721B2Method of using a non-acidic stimulation fluid in high temperature sandstone formations

Publication Date: 2016.05.10 SAUDI ARABIAN OIL CO

AI summary

A three step method of using a non-acidic stimulation fluid in high temperature sandstone formation is provided. The method consists of using a preflush brine, a non-acidic stimulation fluid, and an overflush brine.