Effect of Matrix Acidizing on The Performance of Selected Niger Delta Reservoirs

Abstract

The performance of matrix acidized selected wells from the Tertiary sandstone reservoirs in the Niger/Delta was evaluated, Data obtained was used to evaluate flow efficiency and production performance before and after acidizing. The results showed that Matrix acidizing proven to be the best stimulation technique employed in recent years to remove near wellbore damages and invariably increase productivity. The analysis involves the post net oil and percentage increase in oil achieved after acidizing, well inflow performance quality indicator and decline rate analysis.

Assessment of oil-producing wells by means of stimulation approach through matrix acidizing: a case study in the Azraq region

“…( 14), might be a more acceptable alternative for estimating the success of the acid treatment in case of a dolomite matrix. This facet is consistent with the findings by Civan (2007), Ifeanyi et al (2015), andTiab andDonaldson (2016). However, almost identical values for the (SR), based on (Qs), have been attained for Hummar in relation to those of the Shueib formation.…”

“…The constant parameter (0.1246) has typical SI-units expressed as [s/ m 1/2 ]. The wellbore connectivity parameter ( k d ⋅ H ) is an indication of the oil well productivity from the reservoir; this is consistent with the findings in the literature of Earlougher Jr. (1977), Soare and Bratu (1987), Ifeanyi et al (2015), Tiab andDonaldson (2016), andChukwuma andClifford (2019).…”

“…and Bratu (1987), Patton et al (2003, Morsy et al (2013), El-Naggar et al (2014, Ifeanyi et al (2015), Tiab and Donaldson (2016), Yancheng et al (2017), Chukwuma and Clifford (2019), and Zhang et al (2020), (S) has the values between (-7) to few hundreds in positive domain. Accordingly, positive skin magnitudes increase the estimated (r d ), which physically mean a poor connection is established between the reservoir and the wellbore zone.…”

“…In some applications, mixtures of HCl and hydrofluoric acids (HF) are implemented, which boost the dissolving of sandstones and other silicate content in the reservoir rocks (Tang et al 2002;Thomas et al 2002;Patton et al 2003;Shafiq and Mahmud 2016;Rabbani et al 2018). The technical objectives of well stimulation are to eliminate or bypass the formation damage, therefore reducing the debris production, and the gravel packs are eventually cleaned up (Ifeanyi et al 2015;Ugbenyen 2011;Wilfred and Umeleuma 2015).…”

“…According to the fluid mechanic concepts, hydrostatic pressure (P s ) is calculated by the hydrostatic height (z) oil column in the well, multiplied by the specific gravity (γ) of the well fluid. According to outcomes of Horner plot, the well flow pressure, skin pressure drop, and well (DR) are estimated (Tang et al 2002;Civan 2007;Ahmed 2010;Tiab and Donaldson 2016): where (m) is the pressure variation with the hydrostatic vertical distance, or the so-called pressure gradient, with units of [bar/cycle] and could be evaluated from Horner data of the target reservoir, as was stated in Kolin et al and Kurevija et al (2018); (B) is the oil formation volume factor, defined as the ratio the reservoir's oil volume at the prevailing conditions (temperature, pressure, water saturation) with respect to standard conditions at the surface; (t) is the time interval; (c t ) is total compressibility; (H) is formation thickness; (k d ) is the permeability of damaged zone, (μ) is the oil dynamic viscosity, (P 1hr ) is the interpretation of pressure in Horner plot after 1 h of well shut-in; (Q) is the production rate; (r w ) is wellbore radius; and (T r ) is the well transmissibility that is utilized as a measure of the connectivity parameter of the formation corrected for the viscosity of the flowing hydrocarbon, as was stated by Earlougher Jr. (1977), Soare and Bratu (1987), Ifeanyi et al (2015), Tiab andDonaldson (2016), andChukwuma andClifford (2019). Skin pressure drop, presented in Eq.…”