Production Chemistry

Module 1 - Mixing And Dosage

def mixed_concentration(c1, q1, c2, q2):
    """
    Mix two streams with concentrations c1 and c2.
    Units may be mg/L, ppm, wt%, etc. as long as both match.
    """
    if (q1 + q2) == 0:
        return None
    return (c1 * q1 + c2 * q2) / (q1 + q2)

def product_injection_gpd(water_rate_bpd, target_ppm_active,
                          product_active_frac=1.0,
                          product_density_lb_gal=8.34):
    """
    Daily product requirement for a continuous chemical program.
    target_ppm_active is ppm active in the produced-water stream.
    """
    if product_active_frac <= 0 or product_density_lb_gal <= 0:
        return None
    water_lb_day = water_rate_bpd * 42.0 * 8.34
    active_lb_day = water_lb_day * target_ppm_active / 1e6
    product_lb_day = active_lb_day / product_active_frac
    return product_lb_day / product_density_lb_gal

Common failure mode: teams compare product gallons instead of active ppm. Always normalize to active ingredient.

Module 2 - Squeeze And Near-Wellbore Treatment Volumes

def radial_pore_volume_bbl(rw_ft, re_ft, net_height_ft, porosity,
                           water_saturation=1.0):
    """
    Cylindrical pore volume in reservoir barrels.
    Volume(ft3) = pi * h * (re^2 - rw^2) * phi * Sw
    1 reservoir bbl = 5.615 ft3
    """
    import math
    bulk_ft3 = math.pi * net_height_ft * (re_ft**2 - rw_ft**2)
    pore_ft3 = bulk_ft3 * porosity * water_saturation
    return pore_ft3 / 5.615

def squeeze_slug_bbl(pore_volume_bbl, treated_pv_frac=0.05, overflush_frac=0.25):
    """
    Screening slug and overflush volumes for inhibitor squeeze design.
    """
    slug = pore_volume_bbl * treated_pv_frac
    overflush = slug * overflush_frac
    return {"slug_bbl": slug, "overflush_bbl": overflush,
            "total_bbl": slug + overflush}

Use actual adsorption isotherms, rock mineralogy, and target return profile for final squeeze design. The equations above are screening only.

Module 3 - Corrosion Program Surveillance

def corrosion_rate_mpy(weight_loss_mg, density_g_cm3, area_in2, time_hr):
    """
    Corrosion rate in mils per year from coupon weight loss.
    Standard form: CR(mpy) = 534 * W / (D * A * t)
    """
    if density_g_cm3 <= 0 or area_in2 <= 0 or time_hr <= 0:
        return None
    return 534.0 * weight_loss_mg / (density_g_cm3 * area_in2 * time_hr)

def inhibitor_efficiency(blank_rate, treated_rate):
    """Percent reduction in corrosion rate due to treatment."""
    if blank_rate <= 0:
        return None
    return 100.0 * (blank_rate - treated_rate) / blank_rate

Surveillance hierarchy

1. Coupon or probe trend
2. Iron trend and solids characterization
3. Failure analysis of retrieved metal
4. Only then chemical program adjustment

Module 4 - Troubleshooting Matrix

Module 5 - Cleanup And Reuse Checklist

Before concluding that "the chemistry is bad," check:

• Was the breaker system matched to temperature and residence time?
• Did iron control and oxygen scavenging match the actual flowback period?
• Are returned additives still present at concentrations that affect membranes or sorbents?
• Did a change in separator residence time, shear, or heating create the emulsion problem?
• Did mixed waters change barium, strontium, sulfate, or carbonate saturation?

Output Format

When using this skill, structure the answer as:

1. Confirmed or suspected chemistry failure mode
2. Data normalization and active-ingredient basis
3. Most likely root causes
4. Minimal lab or field tests needed to confirm
5. Operational and chemical actions, in that order

Integration Points

• Use pnge:flow-assurance for hydrate, corrosion, wax, and scale thermodynamics.
• Use pnge:matrix-acidizing for acid cleanup and iron / precipitate risks.
• Use pnge:usgs-produced-waters and pnge:usgs-waterdata for water chemistry context.
• Use the pnge-pw-treatment agent or DLE workflows when reuse or mineral recovery is the objective.