eiru_invoiceid_voucher/views/account_voucher_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
  <data>
    <record model="ir.ui.view" id="sequence_voucher_form">
      <field name="name">sequence_voucher_form</field>
      <field name="model">account.voucher</field>
      <field name="inherit_id" ref="account_voucher.view_vendor_receipt_form"/>
      <field name="arch" type="xml">
      <field name="journal_id" position="before">
          <field name="seq_invoice" readonly="1"/>
          </field>
      </field>
    </record>

    <record id="account_voucherseq_tree_view" model="ir.ui.view">
        <field name="name">account.voucherseq.tree.view</field>
        <field name="model">account.voucher</field>
        <field name="inherit_id" ref="account_voucher.view_voucher_tree"/>
        <field name="arch" type="xml">
            <field name="reference" position="after">
                <field name="seq_invoice"/>
            </field>
        </field>
    </record>

 </data>
</openerp>